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: Anatomy
Downward rotation, medial rotation and extortion of eye ball is facilitated by: 
Select and explain. 
A. Superior rectus, B. Inferior rectus, C. Levator palpebrae superioris, D. Medial rectus
B: Inferior rectus
Answer: B: Inferior rectus 
Explanation: Actions of Individual Muscles



Levator palpabrae superioris
Elevation of upper eyelid


Superior rectus
Upward rotation, medial rotation and intortion


Inferior rectus
Downward rotation, medial rotation and extortion


Medial rectus
Medial rotation


Lateral rectus
Lateral rotation


Superior oblique
Downward rotation, lateral rotation and intortion


Inferior oblique
Upward rotation, and extortion