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: Social & Preventive Medicine
What is Sanchol? 
Select and explain. 
A. Hormonal contraceptive, B. Cholera Vaccine, C. Nutritional supplement, D. Pesticide
B: Cholera Vaccine
Answer: B: Cholera Vaccine 
Explanation: Sanchol and MORCVAX are bivalent oral cholera vaccines based on serogroups O1 and O139. Ref: Park 21st edition, page 211.