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
True about Cholera -a) Food can transmit cholerab) Vaccination gives 90% efficiencyc) Healthy carrier can transmit cholerad) Chlorination is not effective 
Select and explain. 
A. ac, B. bc, C. ad, D. b
A: ac
Answer: A: ac 
Explanation: Cholera is transmitted by contaminated water & food, direct contact through finger from carriers
About Other Options:

Option b: Vaccination gives protection rate of 50–60% ………………. Ananthanarayan 9/e p311
Option d: Chlorination is effective. ‘In rural area, water can be made safe from cholera bacilli by boiling or chlorination’