Homeostasis is the ability of an open system to regulate its internal environment to maintain stable conditions by means of multiple dynamic equilibrium adjustments controlled by interrelated regulation mechanisms. All living organisms, whether unicellular or multicellular exhibit homeostasis. Therefore, the correct answer is option D.

Normal body temperature is 37 degree Celsius. To convert from Celsius to Kelvin add 273. So 37 + 273 = 310 degrees Kelvin.

• In humans, the average internal temperature is 37.0 °C (98.6 °F).
• Hypothermia is a medical emergency that occurs when your body loses heat faster than it can produce heat, causing a dangerously low body temperature.
  
• Hypothermia occurs as your body temperature falls below 35.0 °C.
  
• Hence Human temperature is set at 37.0 °C.
• So, the correct answer is '37.0 °C'.

Tactile sensations are produced by the pressure receptors in the skin. The tactual sensation is related to touch.

Kelvin is the unit of measurement of temperature on an absolute scale. Kelvin temperature scale has an absolute zero below which temperatures do not exist. Absolute zero, is the temperature corresponds to a temperature of - 273.15° on the Celsius scale.The normal temperature of human body is 36.85$^0 $C.   

• Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different.
  
• When the body becomes hotter than the normal temperature the sweat glands releases sweat which in turns cools the skin as it evaporates. This helps the lower internal temperature of the body.
  
• So, the correct answer is 'Sweat-Thermoregulation'.

• Core temperature is regulated by the hypothalamus (in the brain), which is often called the body’s thermostat. 
• The hypothalamus responds to various temperature receptors located throughout the body and makes physiological adjustments to maintain constant core temperature. 
• The human body regulates temperature by keeping a tight balance between heat gain(conduction) and heat loss(convention). And in humans, perspiration (sweating) is primarily a means of thermoregulation. Hence, Temperature of the human body is maintained by Perspiration, Conduction and convection and Radiation. So, the correct answer is 'All of the above'.

Homeostasis is the ability of an organism to maintain a constant internal environment. Homeostasis is maintained by the hypothalamus with the help of negative feedback loops that counteract changes of many characteristics from their set points. For example, when there is a rise in body temperature a negative feedback loop will bring it back to normal towards the set point of 37.5$^o$ C. Hence homeostasis is necessary for the well-being of individual cells and of the entire body. Thus the correct answer is option B.

Our body needs to maintain a 37°C to function properly. If it drops it could damage our organs or brain, so to stop this happening, our body strictly regulates temperature. Shivering is an involuntary pattern of repetitive, rhythmic muscle contractions. This twitching exercise produces heat, which helps to raise body temperature. Thus, the correct answer is option D.

Diencephalon consists of thalamus and hypothalamus. Thalamus serves as a relay station for sensory impulses as well as integration centre for recognition of pain, temperature and hard touch. The thermostat centre for temperature control is present in the hypothalamus. Hypothalamus maintains the constant human body temperature by regulation of the diameter of blood vessels (constriction or dilation), shivering and sweating mechanisms. The pituitary gland is also known as hypophysis. The pituitary gland is mainly concerned with growth and development of organism via its growth hormone and with the regulation of secretion of hormones by other endocrine glands via its tropic hormones. Thus, the correct answer is option B.

• Homeothermy or homeothermy is thermoregulation that maintains a stable internal body temperature regardless of external influence.
• Hypothalamus is the built-in thermostat present in the homeothermic animal's body.
• The hypothalamus controls the body's responses to the outside temperature. When you get hot, you sweat.
  
• Hence Animals with built-in thermostat are Homeothermic.
• So,  the correct answer is 'Homeothermic'.