This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
[{'content': 'Cholera transmission by - \nSelect and explain. \nA. Food transmits, B. Vaccination gives 90% efficiency, C. Healthy carrier, D. Chlorination is nor effective', 'role': 'user'}, {'content': "Answer: A \nExplanation: Mode of transmission of cholera is by - faecally contaminated water. - contaminated foods and drinks. Reference : Park's textbook of preventive and social medicine, 23rd edition, pg no:230 <\\p>", 'role': 'assistant'}]