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': 'The volume of the orbit is about: \nSelect and explain. \nA. 30 cc, B. 40 cc, C. 50 cc, D. 60 cc', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. 30 cc', 'role': 'assistant'}]