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
Action of superior oblique is following except - 
Select and explain. 
A. Extortion, B. Depression, C. Abduction, D. Intortion
A: Extortion
Answer: A: Extortion 
Explanation: Superior oblique causes intorsion (not extorsion).