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
Vibrio cholera was discovered by - 
Select and explain. 
A. Koch, B. Mekintoff, C. John snow, D. Virchow
A: Koch
Answer: A: Koch 
Explanation: Ans. is 'a' i.e., Koch