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': 'Drug–induced colitis is most frequently associated with : \nSelect and explain. \nA. Neomycin, B. Vancomycin, C. Clindamycin, D. Chloramphenicol', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]