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: Pharmacology
Optic neuritis is caused by following, except: 
Select and explain. 
A. Ethambutol, B. Chloroquine, C. Steroid therapy, D. Methanol
C: Steroid therapy
Answer: C: Steroid therapy 
Explanation: Steroid therapy