This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuroanatomy 1, Subject name: Anatomy
[{'content': 'The marked structure is involved in which pathology \nSelect and explain. \nA. Dementia, B. Alzheimer, C. Paralysis agitans, D. Chorea', 'role': 'user'}, {'content': "Answer: C \nExplanation: Marked structure is substantia nigra of brain (dark due to neuro melanin) (in mid-brain) Produce dopamine Lesion +- dopamine decreases - resulting in parkinson's disease / paralysis agitans.", 'role': 'assistant'}]