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: Social & Preventive Medicine
[{'content': 'Not a pyTethram derivative? \nSelect and explain. \nA. Cypermethrin, B. Penncthrin, C. DDT, D. Resmethrin', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., DDT", 'role': 'assistant'}]