What is the largest part of the brain responsible for voluntary muscular activity and memory?

The largest part of the brain is the cerebrum, which plays a crucial role in various complex functions. It is primarily responsible for voluntary muscular activity, allowing individuals to control their movements consciously, such as reaching for an object or walking. The cerebrum also houses critical areas involved in memory, learning, and higher-level cognitive functions, enabling us to recall information, make decisions, and solve problems.

In contrast, the cerebellum primarily coordinates balance and fine motor skills rather than voluntary movements. The medulla oblongata and pons are part of the brainstem, responsible for regulating involuntary functions, such as heartbeat and respiration, rather than the voluntary actions and memory attributed to the cerebrum. Thus, the cerebrum's extensive involvement in voluntary activities and memory makes it the correct answer to this question.