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': 'Red man syndrome is due to: \nSelect and explain. \nA. Vancomycin, B. Polymyxin, C. Rifampicin, D. Teicoplanin', 'role': 'user'}, {'content': "Answer: A \nExplanation: Vancomycin has the potential to release histamine by direct action on mast cells. Rapid i.v. injection has caused chills, fever, urticaria and intense flushing-called ' Red man syndrome'.\nReference: Essentials of Medical Pharmacology Eighth Edition KD\xa0TRIPATHI\xa0page no 806", 'role': 'assistant'}]