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': 'Trabecular (conventional) outflow of aqueous humour accounts for: \nSelect and explain. \nA. 90 percent, B. 80 percent, C. 70 percent, D. 60 percent', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. 90 percent', 'role': 'assistant'}]