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
Red man syndrome is caused by 
Select and explain. 
A. Vancomycin, B. Teicoplanin, C. Both 1 & 2, D. Ciprofloxacin
A: Vancomycin
Answer: A: Vancomycin 
Explanation: Vacomycin can release histamine & lead to "Red man syndrome".