This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti Microbial, Subject name: Pharmacology
[{'content': 'Vancomycin is used orally for treatment of \nSelect and explain. \nA. Hepatic encephalopathy, B. Pseudomembranous colitis, C. Staphylococcal food poisoning, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref: Sharma & Sharma 3rd ed. P 742-43; Katzung, 14th ed. pg. 809* Vancomycin (oral) is now considered as the drug of choice for pseudomembraneous colitis.* Metronidazole also used for pseudomembraneous colitis in mild cases.* Ampicillin has been associated with pseudomembranous colitis* Ceftriaxone is DOC for typhoid/enteric fever. Should be given IV.* METRONIDAZOLE is also the drug of choice in the treatment of amebiasis, trichomoniasis, Giardiasis and extraluminal amebiasis.* For serious pseudomembranous colitis not responding to metronidazole, DOC is Vancomycin', 'role': 'assistant'}]