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 muscle which makes an angle of about 23deg with the optical axis is: \nSelect and explain. \nA. Superior oblique, B. Superior rectus, C. Inferior oblique, D. Medial rectus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Superior rectus', 'role': 'assistant'}]