This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Physiology
[{'content': 'Motor aphasia refers to defect in \nSelect and explain. \nA. Peripheral speech apparatus, B. Verbal expression, C. Auditory comprehension, D. Verbal comprehension', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In nonfluent aphasia, the lesion is in Broca area. Speech is slow, and words are hard to come by. Patients with severe damage to this area are limited to two or three words with which to express the whole range of meaning and emotion. Sometimes the words retained are those that were being spoken at the time of the injury or vascular accident that caused the aphasia.', 'role': 'assistant'}]