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: Anatomy
[{'content': 'Ptosis is due to damage of : \nSelect and explain. \nA. Occulomotor nerve, B. Abducens nerve, C. Trochlear nerve, D. Facial nerve', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]