This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of orbit, Lids and lacrimal apparatus, Subject name: Ophthalmology
[{'content': 'Most common ocular foreign body is \nSelect and explain. \nA. Chisel and hammer, B. Glass, C. Plastic, D. Stone', 'role': 'user'}, {'content': 'Answer: A \nExplanation: most common occular foreign body is iron. And the most common mode is chissel and hammer Refer khurana 6/e p 421', 'role': 'assistant'}]