___is made of a cerebral cortex of gray matter which surrounds white matter.Group of answer choicesbrainstemmedulla oblongatacerebrumcerebellum

The correct answer to the question is "cerebrum."

Explanation:

1. The cerebral cortex, which is made of gray matter, is the outer layer of the cerebrum.
2. The white matter lies beneath the gray matter cortex in the cerebrum.
3. Other options:
   • The brainstem primarily contains white matter, with the gray matter concentrated in the nuclei.
   • The medulla oblongata is part of the brainstem and mainly consists of white matter.
   • The cerebellum has a layer of gray matter on the surface, but it is not primarily identified by the gray matter surrounding white matter as the cerebrum is.

Therefore, the cerebrum is indeed characterized by having a cerebral cortex of gray matter surrounding white matter.