This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Health care of community & international health, Subject name: Social & Preventive Medicine
World Anti Tobacco Day is observed on 
Select and explain. 
A. 31st May, B. 5th June, C. 12th July, D. 24th November
A: 31st May
Answer: A: 31st May 
Explanation: Ref: 25th Ed K.Park's Textbook Of Preventive and Social Medicine