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: Ophthalmology
[{'content': "Horner's syndrome, all are true except: \nSelect and explain. \nA. Unilateral loss of sweating, B. Enophthalmos, C. Mydriasis, D. Ptosis", 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Mydriasis', 'role': 'assistant'}]