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': 'Earliest clinical feature of orbital extension of the basal cell carcinoma of the eyelid is \nSelect and explain. \nA. Diplopia, B. Photophobia, C. Leucocoria, D. Proptosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]