The correct option is A Brain
The main function of the brain is to integrate the sensory inputs from the internal and external environment as received by sensory neurons. They are then processed and finally, the nerve impulses are transmitted to the effector organs (muscles and glands). Thus, being the center of processing information, the brain has the maximum number of neurons. Since the cell body is a part of a neuron, therefore, it can be concluded that the brain has the largest number of cell bodies.