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': 'Volume of the vitreous is: \nSelect and explain. \nA. 2 mL, B. 3 mL, C. 4 mL, D. 7 mL', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. 4 mL', 'role': 'assistant'}]