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
Eth-A gene mutation can lead to cross resistance of Ethionamide with: 
Select and explain. 
A. PAS, B. Isoniazid, C. Ethambutol, D. Thioacetazone
D: Thioacetazone
Answer: D: Thioacetazone 
Explanation: Eth-A gene encodes Monoxygenase enzyme that activates both Ethionamide and Thioacetazone. Therefore mutation of Eth-A gene is responsible for resistance in both Ethionamide and Thioacetazone.