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
Hypothyroidism may be caused by- 
Select and explain. 
A. Ethionamide, B. Thiocetazone, C. Ethambutol, D. Streptomycin
A: Ethionamide
Answer: A: Ethionamide 
Explanation: Ans. is 'a' i.e., Ethionamide