This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
Ethambutol causes 
Select and explain. 
A. Retro bulbar neuritis, B. Deafness, C. Red urine, D. Peripheral neuritis
A: Retro bulbar neuritis
Answer: A: Retro bulbar neuritis 
Explanation: Refer Katzung 10/e p774 KDT 6/e p 742 Ethambutol causes retobulbar neuritis It can result in red green colour blindness