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
A boy presents with eye deted laterally and slightly downward. The upward gaze is impaired and medial rotation is not possible. Which nerve is involved. 
Select and explain. 
A. III, B. IV, C. V, D. All
A: III
Answer: A: III 
Explanation: A. i.e. III