The correct answer is incomplete as it lacks the options, however the answer is given on based of generalized role:
Answer:
The correct answer is- CSF provides a near-water medium for diffusion of nutrients and cushions the brain.
Step-by-step explanation:
Cerebrospinal fluid is colorless body fluid present in the spinal cord, and the brain. This fluids play a vital role in human body to protect brain by acting as the cushion for the brain and protect from external shock.
CSF also play role in diffusion as it provides the water like medium that help in the diffusion process of nutrients in the body.
Thus, the correct answer is - CSF provides a near-water medium for diffusion of nutrients and cushions the brain.