World Blood Donor Day, dedicated to voluntary blood donation, is observed every year on which of the following dates?

Introduction / Context:
This question focuses on an important health-awareness observance related to blood donation. World Blood Donor Day highlights the critical role of voluntary, unpaid blood donors in saving lives. Knowing the date is useful for exams and also for understanding how health organisations schedule awareness campaigns around the year.

Given Data / Assumptions:

• The observance is World Blood Donor Day.
• The options are 14 June, 24 June, 14 November, and 24 November.
• We must select the date that is officially recognised for this day.

Concept / Approach:
World Blood Donor Day is celebrated on 14 June each year. The date honours the birthday of Karl Landsteiner, the Nobel Prize-winning scientist who discovered the ABO blood group system. Awareness campaigns on this day emphasise the need for safe blood and blood products. The other listed dates are used for different observances or are simply distractors placed near the correct date to confuse candidates.

Step-by-Step Solution:
Step 1: Identify that the question is about World Blood Donor Day, a WHO-related awareness day. Step 2: Recall that World Blood Donor Day is observed on 14 June every year to honour blood donors and the work of Karl Landsteiner. Step 3: Compare with the options: 14 June, 24 June, 14 November, and 24 November. Step 4: Confirm that 14 June matches the official date listed by WHO and national health ministries. Step 5: Recognise that 24 June and the November dates are unrelated to World Blood Donor Day in standard GK references. Step 6: Select 14 June as the correct answer.

Verification / Alternative check:
World Health Organization documents, national blood-transfusion services, and health-awareness calendars consistently show World Blood Donor Day on 14 June. This date is celebrated through blood donation camps, awareness posters, and social media campaigns, confirming that our answer is reliable.

Why Other Options Are Wrong:
24 June: Not linked to World Blood Donor Day and used here only as a close distractor.
14 November: Known more for World Diabetes Day in GK, not for blood donation.
24 November: Not a standard date for this observance and has no official link with World Blood Donor Day.

Common Pitfalls:
A typical error is mixing up 14 June with other 14th-of-the-month observances, especially 14 November, which is World Diabetes Day. The best way to avoid confusion is to remember simple associations: 14 June for blood donation and 14 November for diabetes. Linking each date with its theme helps retain the information more clearly.

Final Answer:
Therefore, World Blood Donor Day is observed every year on 14 June.