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
All of the following statements about cholera are true except - 
Select and explain. 
A. 0 & H antigens measure carrier state, B. Culture medium is TCBS Agar, C. Produces indole and reduces nitrate, D. Synthesize neuraminidase
A: 0 & H antigens measure carrier state
Answer: A: 0 & H antigens measure carrier state 
Explanation: Ans. is 'a' i.e., 0 & H antigens measure carrier state