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
WHO formation day is 
Select and explain. 
A. 5-May, B. 7 April, C. 10-Jun, D. 10-Jul
B: 7 April
Answer: B: 7 April 
Explanation: None