This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy: General Principles, Subject name: Pharmacology
Drug of choice for antibiotic associated pseudomembranous colitis is: 
Select and explain. 
A. Oral vancomycin, B. Metronidazole, C. Clindamycin, D. Penicillin G
A: Oral vancomycin
Answer: A: Oral vancomycin 
Explanation: Ans. (A) Oral vancomycin(Ref: CMDT 2019/661)According to new guidelines, oral vancomycin is drug of choice for pseudomembranous colitis