Answer:
The correct answer is C) arachnoid mater.
Explanation:
Arachnoid mater, along with pia mater and dura mater, form the meninges, a very thick membrane that protects the brain and the spinal cord. The arachnoid mater is in the middle of the other two layers and it is very important since it holds the cerebrospinal fluid (CSF) in its interior. Arachnoid mater has finger-like projections that enter the dural venous sinuses and are called arachnoid villi. These villi are responsible for the diffusion of CSF into the blood.
