World Tuberculosis Day is observed every year to raise public awareness about tuberculosis and efforts to eliminate this disease. On which date is World Tuberculosis Day celebrated globally?

Introduction / Context:
World Tuberculosis Day is a major health related international observance. It marks the day when Robert Koch announced the discovery of the tuberculosis bacterium, an event that changed the understanding and treatment of the disease. Knowing the exact date of this observance is important for general knowledge, especially for questions related to health, disease control, and World Health Organization campaigns.

Given Data / Assumptions:

• The observance is named World Tuberculosis Day.
• It focuses on awareness about tuberculosis, sometimes abbreviated as TB.
• The day is celebrated on a fixed date every year.
• The provided options are four different dates in March.

Concept / Approach:
World Tuberculosis Day is observed on 24 March every year. The date commemorates 24 March 1882, when Robert Koch announced that he had discovered the bacterium that causes tuberculosis. To answer this question correctly, you should associate tuberculosis awareness with the specific date of 24 March and remember that the month is March, not April or another time of the year. Since all options here fall in March, close reading of the exact day is critical.

Step-by-Step Solution:
Step 1: Recall that World Tuberculosis Day is observed in March.Step 2: Remember the historic event in 1882 when Robert Koch made his announcement on 24 March.Step 3: Scan the options and look specifically for 24 March.Step 4: Option C clearly states 24 March.Step 5: Mark option C as the correct answer after confirming that the other dates do not match the known observance.

Verification / Alternative check:
You can verify this information by recalling World Health Organization campaigns that are widely covered by media in late March, often with slogans about ending TB and preventing drug resistant forms of the disease. These campaigns consistently mention 24 March as World Tuberculosis Day. Another verification method is to remember the link between Koch's discovery and the formal observance date chosen to honour that milestone in medical history.

Why Other Options Are Wrong:
21 March is close to the correct date but does not coincide with the historic announcement and is not recognised as World Tuberculosis Day.
23 March is one day before the official observance and is sometimes chosen as a trap option to confuse careless readers.
22 March is used for other international days such as World Water Day and does not mark TB awareness.

Common Pitfalls:
The main pitfall is mixing 24 March with 22 March or 23 March, especially when candidates memorise dates in a hurry without linking them to the underlying historical event. Another common error is to confuse World Tuberculosis Day with World Health Day on 7 April or other disease specific days. To avoid this, always connect each health observance with a story or key fact such as a discovery or founding date, rather than relying only on bare numbers.

Final Answer:
The correct date is 24 March.