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
[{'content': 'Ethambutol causes \nSelect and explain. \nA. Retro bulbar neuritis, B. Deafness, C. Red urine, D. Peripheral neuritis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Refer Katzung 10/e p774 KDT 6/e p 742 Ethambutol causes retobulbar neuritis It can result in red green colour blindness', 'role': 'assistant'}]