Final answer:
Mental rotation occurs primarily in the parietal lobe of the brain, which is responsible for processing spatial orientation and movement.
Step-by-step explanation:
Mental rotation tasks are believed to be processed in the parietal lobe of the brain. This is supported by the lobes' various responsibilities; while the frontal lobe is largely involved in motor functions, cognitive functions, and personality, the parietal lobe is engaged in processing somatosensation and proprioception, which are related to understanding spatial orientation and movement. Thus, when considering tasks that involve the mental manipulation of objects in space, such as mental rotation, the parietal lobe is the area chiefly responsible. This means the correct answer to the question about the area of the brain where mental rotation occurs is B) Parietal Lobe.