This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Orbit, Subject name: Anatomy
Primary action of inferior oblique muscle is - 
Select and explain. 
A. Abduction, B. Adduction, C. Extorsion, D. Elevation
C: Extorsion
Answer: C: Extorsion 
Explanation: Ans. is 'c' i.e., Extorsion MusclePrimary ActionSecondary ActionSuperior rectusElevationAdduction and intorsionInferior rectusDepressionAdduction and extorsionMedial rectusAdduction Lateral rectusAbduction Superior obliqueIntorsionAbduction and depressionInferior obliqueExtorsionAbduction and elevation