Final answer:
The pia mater is the innermost layer of the meninges that adheres directly to the brain and spinal cord, unlike the outermost dura mater layer, which is thicker and contains vein-like structures.
Step-by-step explanation:
The correct statement regarding the pia mater is: B) It adheres directly to the surface of the brain and spinal cord. The pia mater is the innermost layer of the meninges, which is the series of membranes that protect the central nervous system (CNS), comprising the brain and spinal cord. Unlike the dura mater, which is the outermost and thickest layer, the pia mater is a thin fibrous membrane that closely follows the contours of the brain, entering the sulci and fissures. It is considered the delicate and tender layer that provides a gentle covering, much like plastic wrap, for the brain's surface. In contrast, the dura mater is a tough protective sheath across the CNS and is known to contain vein-like structures which include the dural sinuses that carry blood back to the heart.