What are the 3 essential components of the skull?

A. The skull contains and protects three essential components: brain tissue, blood, and cerebrospinal fluid (CSF), which together maintain intracranial pressure and brain function. B. White matter and grey matter are parts of the brain, but "yellow matter" is not a recognized term. C. Synovial fluid is found in joints, not in the skull; spinal fluid refers to CSF but listing both is redundant. D. WBCs, leukocytes, and plasma are components of blood, not components contained within the skull.