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
[{'content': 'First line of antitubercular drug is: \nSelect and explain. \nA. Streptomycin, B. INH, C. Ethambutol, D. Cephalosporins', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]