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': 'Not a feature of Homer syndrome \nSelect and explain. \nA. Exophthalmos, B. Ptosis of upper eyelid, C. Miosis, D. Conjuctival congestion', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Exophthalmos', 'role': 'assistant'}]