This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti Microbial, Subject name: Pharmacology
[{'content': 'Which drug predisposes to pyloric stenosis in infants - \nSelect and explain. \nA. Erythromycin, B. Streptomycin, C. Tetracycline, D. Nitrofurantoin', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Erythromycino Maternal and infant use of erythromycin and other macrolide antibiotics have been reported as riks factors for infantile hypertrophic pyloric stenosis (IHPS).", 'role': 'assistant'}]