This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuro-Ophthalmology, Subject name: Ophthalmology
Which one of the following is an oculotoxic drug? 
Select and explain. 
A. Isoniazid, B. Ethambutol, C. Streptomycin, D. Rifampin
B: Ethambutol
Answer: B: Ethambutol 
Explanation: Ans. (b) EthambutolRef: Parson's 22/e, p. 244, 366; Kanski 7/e, p. 868)Visual symptoms or toxic optic neuropathy occurs more commonly if dose exceeds 25 mg/kg/day. Patient experiences red-green colour blindness and blurring