An automatic (involuntary) neuromuscular action excited by a defined stimulus is called reflex action. Sweating is not a reflex action. It is primarily a means of temperature regulation. But, Salivation and hand withdrawal because of the needle both are reflex actions.

Option 'D' is correct

Voluntary movements are movements that are in direct control of the will of a person. These are controlled by skeletal muscles. For example walking, talking, dancing, etc. Involuntary movements are movements that are not in control of a person. They are generated by smooth striated muscle. For example, heart pumping, digestion, etc. 

Medulla oblongata is the part of hindbrain. It is located in the brainstem, anterior to the cerebellum. It controls the involuntary functions . It is linked to the autonomic system and has cardiac, respiratory, vomiting and vasomotor centres. It also controls breathing heart rate and blood pressure.

Each kind of a change in the environment evokes an appropriate movement in response. When we want to talk to our friends in class, we whisper, rather than shouting loudly. So, the movement to be made depends on the event triggering it. Hence, such controlled movement must be connected to the recognition of various events in the environment, followed by only the correct movement in response. Therefore, the correct answer is option A.

Reflex action is an action which is given in response to something in the environment. It is an immediate action taken without much thinking and it does not have our control. The spinal cord is responsible for the response of the body because the impulse has not reached the brain till then. Therefore, the correct answer is option A.

• Voluntary actions are those which can be controlled by us like clapping, dancing, jumping, running, etc. 
• Whereas, involuntary actions are those which cannot be regulated or stopped by us like the circulation of blood, heartbeat, etc. Hence, reflex actions are involuntary actions that are done to save oneself from danger. 

• The best-known reflex is the pupillary light reflex. If a light is flashed near one eye, the pupils of both eyes contract.
•  Light is the stimulus, impulses reach the brain via the optic nerve, and the response is conveyed to the pupillary musculature by autonomic nerves. 

Involuntary actions are the actions which are happening without the conscious choice of an organism. The examples for involuntary actions are: Vomiting, yawning, salivation, heart beats, coughing, sneezing, etc.  Whereas chewing is a voluntary action, which is controllable.

Reflex action is an involuntary action and it is a sudden reaction against the stimulus. e.g. removal of hand on being touched by hot or insertion of a pin in a skin, coughing, closing of the eyelid when any object enters in the eye

There are two types of reflex arcs namely, autonomic (visceral) reflex arc, affecting inner organs and somatic reflex arc, affecting muscles. 

• The movement of animals towards or away from the stimulus is called as the taxis. The taxis may be negative or positive. 
• The movement away from a stimulus is called negative taxis and the movement towards the stimulus is called positive taxis.

• A simple reflex arc consists of only one sensory neuron and one motor neuron, hence the name is the monosynaptic reflex. A complex reflex arc or polysynaptic reflex is formed when the sensory neuron influences several motor neurons through intermediate (association) neurons of the spinal cord. Complex reflex arc consisting of two sensory neurons and one motor neuron.

A sleeping cat suddenly gets up and chases a rat. The movement involved is similar to the movement of train on green signal, because it is involuntary action.

So, the correct option is ‘the movement of train on green signal’.

The somatic reflex arc affects the muscles and the receptor organ is skin whereas, the effector organ is skeletal muscles. The visceral reflex arc affects the internal organs and the receptor organ is epithelial lining of the gut whereas, the effector organ is smooth muscles. 

A reflex arc is a simple nervous pathway and consists of the sensory receptor, afferent neuron, center, efferent neuron and effector organ. 

• Digestion of food, contraction, and relaxation of blood vessels and many other movements are involuntary as we cannot really start or stop them simply by our will. 

• Spinal reflex or withdrawal reflex protects the body from the damaging stimulus. 
• It is located in the spinal cord. In this reflex pathway, more than one relay neuron connects the sensory and motor neuron.

• Reflex arc involves both peripheral and central nervous systems. As the route followed by nerve impulses in the production of a reflex act, is from the peripheral receptor organ, through the afferent nerve, to the central nervous system synapse, and then through the efferent nerve, to the effector organ. 

• The reflex actions which involve the brain are called as the cerebral reflex. The autonomic reflex is the one that involves inner organs and the somatic reflex is one that involves the muscles. 

• Reflex arcs have evolved in animals because the thinking process of the brain is not fast enough. 
• Many animals do not have complex neuron networks which is needed for thinking and it is considered efficient. It is a neural pathway that controls a reflex action, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. 
• This characteristic allows reflex actions to occur relatively quickly by activating spinal motor neurons without the delay of routing signals through the brain, although the brain will receive sensory input while the reflex is carried out. 
• Analysis of the signal takes place after the action has been taken. 

• The movement mentioned in the above question are regular activities done by animals and humans. 
• They are not associated with growth, as growth does not depend on these movements. The stop and start of these activities does not regulate growth.