This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Demography and family planning, Subject name: Social & Preventive Medicine
[{'content': 'Census population count is in reference to \nSelect and explain. \nA. 1st March, B. 1st July, C. 30th June, D. 1st January', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Census stop (census movement) : 00. 00 hours 01 March 2011 (The referral time and date at which snapshot of population is taken) Ref: National health programs of India by Dr. J. Kishore, 7th edition Pgno : 572,662', 'role': 'assistant'}]