This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Time Distribution, Epidemics, Subject name: Social & Preventive Medicine
First step in investigation of an epidemic is:- 
Select and explain. 
A. Source identification, B. Verification of the diagnosis, C. Confirmation of existence of epidemic, D. Formation of hypothesis
B: Verification of the diagnosis
Answer: B: Verification of the diagnosis 
Explanation: Investigation of an epidemic-chronological steps: 1) Verification of diagnosis - 1st step2) Confirmation of existence of epidemic 3) Defining population at risk 4) Rapid search of all cases and their characteristics 5) Data analysis 6) Formation of hypothesis 7) Testing of hypothesis 8) Evaluation of ecological factor 9) Fuher investigation of population at risk 10) Writing the repo