This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'All are true regarding pseudomembranous colitis, except \nSelect and explain. \nA. It is caused by clostridium difficile, B. The organism is a normal commensal of gut, C. It is due to production of phospholipase A, D. It is treated by vancomycin', 'role': 'user'}, {'content': "Answer: C \nExplanation: Clostridium difficile causes acute colitis with bloody diarrhea and pseudomembranous colitis. A common cause of nosocomial diarrhea. The disease follows the use of broad-spectrum antibiotics to which it is resistant. Exotoxin A and B involved in the pathogenesis. It is not a normal commensal, it is an oppounistic organism. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 270", 'role': 'assistant'}]