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
In an epidemic first to be done is- 
Select and explain. 
A. Identity the cases, B. Confirm the diagnosis, C. Identify the prone people, D. Identify the causative factors
B: Confirm the diagnosis
Answer: B: Confirm the diagnosis 
Explanation: None