This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'Which part of spinal cord is involved in poliomyelitis? \nSelect and explain. \nA. Posterior horn, B. Lateral column, C. Posterior column, D. Anterior horn', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]