The correct answer is B. Cerebrum.
The cerebrum is the largest part of the human brain, accounting for about 85% of its mass. It is divided into two hemispheres, the left and right hemispheres, which are connected by a bundle of nerve fibers called the corpus callosum. The cerebrum is responsible for higher-order functions such as thought, memory, language, and consciousness.
The cerebellum is the second largest part of the brain. It is located at the back of the brain, below the cerebrum. The cerebellum is responsible for coordination and balance.
The olfactory bulb is a small, bulb-shaped structure located at the base of the brain. It is responsible for the sense of smell.
The midbrain is a small, narrow structure located between the cerebrum and the hindbrain. It is responsible for a variety of functions, including vision, hearing, and movement.