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 23deg with the optical axis is: 
Select and explain. 
A. Superior oblique, B. Superior rectus, C. Inferior oblique, D. Medial rectus
B: Superior rectus
Answer: B: Superior rectus 
Explanation: Ans. Superior rectus