Which region of the brain is involved in conscious activities such as perception and planning?

The cerebrum is the largest part of the brain and plays a crucial role in a variety of conscious activities. It is primarily responsible for higher brain functions such as perception, thought processes, reasoning, and planning. The cerebral cortex, which is the outer layer of the cerebrum, contains areas dedicated to processing sensory information and coordinating voluntary movements, signaling its central role in conscious awareness.

In contrast, the cerebellum is mainly involved in the coordination of movement and balance rather than conscious perception or planning. The thalamus serves as a relay station for sensory information, directing it to appropriate areas of the cerebrum but not directly involved in the conscious processing itself. The medulla, located at the base of the brainstem, controls involuntary functions such as breathing and heart rate and does not play a role in conscious activities. Therefore, the cerebrum is the correct answer, as it encompasses the structures that enable conscious thought and planning.