Answer:
d. cerebrospinal fluid (CSF)
Step-by-step explanation:
Cerebrospinal fluid (CSF) is cololess, clear body fluid that is found in the brain and the spinal cord in the body. It is produced in the body by particularised ependymal cells which are present in the choroid plexuses of ventricles of brain, and are absorbed in arachnoid granulations.
CSF in the body acts as cushion or a buffer for brain which provides basic mechanical as well as immunological protection to brain inside skull.
CSF in the brain moves in single direction outwardly from the ventricles, but in multidirectional in subarachnoid space.
Hence, option D is correct