The correct option is D meninges
The brain and the spinal cord are parts of the central nervous system. The brain and the spinal cord are enclosed by the skull and the vertebrae respectively. The brain and spinal cord together are covered by cranial meninges - dura mater, archanoid mater and the pia mater. They provide a supportive framework for the cerebral and cranial vasculature.
Cerebral aquduct is present within the midbrain and contains the cerebrospinal fluid.