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
The muscle which makes an angle of about 51deg with the optical axis is: 
Select and explain. 
A. Superior rectus, B. Superior oblique, C. Inferior rectus, D. Lateral rectus
B: Superior oblique
Answer: B: Superior oblique 
Explanation: Ans. Superior oblique