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: Microbiology
Gas gangrene is/are caused by- 
Select and explain. 
A. C. novyi, B. C. septicum, C. C. histolyticum, D. All
D: All
Answer: D: All 
Explanation: Ans. is 'a' i.e., C.novyi 'b' C.septicum; 'c' i.e., C. histolyticum