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': "Von Herick angle grade '3' of anterior chamber denotes \nSelect and explain. \nA. Wide open angle, B. Moderately open angle, C. Moderately narrow angle, D. Closed angle", 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Moderately open angle", 'role': 'assistant'}]