World No Tobacco Day (WNTD) is observed each year to highlight the health risks of tobacco use and to advocate for effective policies to reduce tobacco consumption. On which date is World No Tobacco Day celebrated annually?

Introduction / Context:
World No Tobacco Day is a key global health observance coordinated by the World Health Organization. It focuses on the dangers of tobacco use and the need for strong policy measures such as higher taxes, health warnings, and public awareness campaigns. Many exam questions check the exact date of this day because it is an important part of international health calendars and public health current affairs.

Given Data / Assumptions:

• The observance is called World No Tobacco Day and is abbreviated as WNTD.
• It is celebrated once every year on the same date.
• We are asked to identify the correct calendar date.
• Four options provide different dates across various months.

Concept / Approach:
The crucial fact to remember is that World No Tobacco Day is observed every year on 31 May. This timing allows global health agencies and governments to run campaigns just before World Environment Day, emphasizing the impact of tobacco not only on personal health but also on the environment. The approach is to recall this fixed date and then cross check that it appears exactly in one of the options given in the question.

Step-by-Step Solution:
Step 1: Recall that World No Tobacco Day is at the end of May, not in July, August, or October.Step 2: Scan the options and identify which one falls in May.Step 3: Option A states 31 May, which matches the known date for World No Tobacco Day.Step 4: Confirm that none of the other options refer to this campaign in standard general knowledge lists.Step 5: Select 31 May as the correct answer with confidence.

Verification / Alternative check:
One way to verify is to recall that World Health Organization materials and exam based current affairs lists always describe World No Tobacco Day as being held on 31 May. News reports and government press releases also consistently mention this date. If you have previously read about themes like plain packaging, smoke free policies, or youth and tobacco around the end of May, that further reinforces the association between 31 May and this observance.

Why Other Options Are Wrong:
27 August does not correspond to World No Tobacco Day in any standard international observance calendar and is a distractor here.
16 October is known for World Food Day and is linked with the Food and Agriculture Organization, not with tobacco related campaigns.
11 July is used for other international days such as World Population Day and therefore does not match the tobacco focus.

Common Pitfalls:
Candidates sometimes confuse 31 May with 1 June or 31 May with 31 March, especially when they study multiple health days at once. Another common error is mixing up World No Tobacco Day with World Health Day, which falls on 7 April. To avoid such confusion, revise a small list of core World Health Organization days and create easy memory links, such as remembering that the month of May ends with a strong message against tobacco. Careful reading of the options and focusing on the month as well as the day helps reduce guesswork.

Final Answer:
The correct date is 31 May.