The primary function of CSF is to cushion the brain within the skull and serve as a shock absorber for the central nervous system. CSF also circulates nutrients and chemicals filtered from the blood and removes waste products from the brain.

The total volume of CSF in the adult ranges from 140 to 270 ml. The volume of the ventricles is about 25 ml. CSF is produced at a rate of 0.2 - 0.7 ml per minute or 600-700 ml per day.

Cerebrospinal fluid (CSF) is a clear, colorless body fluid found in the brain and spine. It is located in the subarachnoid space between the arachnoid mater and the pia mater. It acts as a cushion for the brain's cortex by providing mechanical and immunological protection to the brain inside the skull. Hence option B is correct.

The choroid plexus is a nerve complex in the ventricles of the brain, where cerebrospinal fluid (CSF) is produced. The choroid plexus consists of modified ependymal cells. 

Cerebrospinal fluid (CSF),  is an alkaline fluid present in the brain and spinal chord. It is formed primarily, in the ventricles of the brain. It supports the brain and provides lubrication between surrounding bones and the brain and spinal cord. It act as buffer for the cerebrum.
So, the correct answer is option B.

The cavities of the central nervous system are called the ventricles that are lined with the choroid plexus. The choroid plexus is made up of the inserted piamater, blood vessels, the ependymal cells. It is responsible for the formation of the formation of the extracellular fluid called the cerebrospinal fluid which drains the ventricles of the brain and spinal cord. The CSF is responsible for collecting the waste from the interstitial space, distribution of nutrients to the brain and spinal cord, act as shock collector during injuries and moistening of the central nervous system.

The choroid plexus is made up of the piamater that is merged into the ventricles, blood capillaries and the ependymal cells that are epithelial cells. The ventricles of the brain contain the choroid plexus. Its function is to produce the cerebrospinal fluid (CSF). The CSF flows from the ventricles into the subarachnoid space through the Foramen of Magendie and Foramen of Luschka. Here it is absorbed by the arachnoid villi and secreted into the cranial venous sinus. From the cranial venous sinus, the CSF enters the blood circulation.

The central nervous system consists of the brain and the spinal cord. The cavities of the central nervous system are called the ventricles that are lined with the choroid plexus. The choroid plexus is made up of the inserted piamater, blood vessels, the ependymal cells. It is responsible for the formation of the formation of the extracellular fluid called the cerebrospinal fluid which drains the ventricles of the brain and spinal cord. The CSF returns to blood via the arachnoid villi.

• CSF protects the brain and spinal cord from trauma.
• CSF supplies nutrients to nervous system tissue.
• CSF removes waste products from cerebral metabolism.