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
Earliest clinical feature of orbital extension of the basal cell carcinoma of the eyelid is 
Select and explain. 
A. Diplopia, B. Photophobia, C. Leucocoria, D. Proptosis
A: Diplopia
Answer: A: Diplopia 
Explanation: None