Which structure connects the left and right hemispheres of the brain?

The corpus callosum is the structure that connects the left and right hemispheres of the brain. It is a large band of neural fibers that facilitates communication between the two hemispheres, allowing for the coordination of activities and processing of information. This structure plays a crucial role in integrating sensory and cognitive functions, enabling the left and right sides of the brain to work together efficiently.

Other options, such as the cerebellum, cortex, and hippocampus, serve different functions. The cerebellum is primarily involved in motor control and coordination, the cortex is the outer layer of the brain responsible for higher-order functions like sensory perception and decision-making, and the hippocampus is key in memory formation and spatial navigation. These structures do not serve the purpose of connecting hemispheres, which is the specific function of the corpus callosum.