What are the key components of the extrapyramidal system in the brain?

The correct answer is B) The extrapyramidal system includes components like the basal ganglia, substantia nigra, and subthalamic nucleus. These structures play a central role in regulating motor functions and are responsible for coordinating movements, posture, and muscle tone. While the cerebellum plays a role in motor coordination, it is not typically considered part of the extrapyramidal system. The corticospinal tracts are part of the pyramidal system, not the extrapyramidal system. The upper motor neurons and the reticular formation are not the primary components of the extrapyramidal system; they are involved in other motor functions. The primary motor cortex and the pyramidal tracts are part of the pyramidal system, not the extrapyramidal system.