Final answer:
The cerebrum and cerebellum both have a cortex, while the medulla oblongata does not. Thus, the correct answer is D. cerebrum and cerebellum.
Step-by-step explanation:
The brain area(s) that have a cortex are D. cerebrum and cerebellum. The cerebral cortex is the thin layer of gray matter on the outside of the cerebrum and is involved in high-level functions such as memory, learning, language, and perception. The cerebellum, often referred to as the "little brain," is also covered by a layer of cortex that helps in coordinating skeletal muscle activity and is important for balance, coordination, movement, and certain types of memory processing.
The medulla oblongata, on the other hand, does not have a layered cortex. It is part of the brainstem along with the pons and midbrain and is involved in regulating vital functions like breathing and heart rate.