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 to be avoided in a patient allergic to penicillin is: \nSelect and explain. \nA. Sulphonamide, B. Tetracycline, C. Ampicillin, D. Chloramphenicol', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]