When the world biodiversity Day is observed?

1. A

   March, 22

   (a) March, 22. 22 March is World Water Day, not the biodiversity day.

2. B

   May, 22

   (b) May, 22. The International Day for Biological Diversity is 22 May, marking the 1992 Nairobi adoption of the CBD text. That stored date is the official key.

3. C

   June, 23

   (c) June, 23. 23 June is not the UN biodiversity date; 5 June is World Environment Day.

4. D

   April, 16

   (d) April, 16. 16 April is not the CBD biodiversity day (Earth Day is 22 April, a neighbour trap).

Summary. Official key is (b) May, 22. World Biodiversity Day is 22 May. 22 March is Water Day; June and April dates on the list are wrong. Neighbouring days are 5 June Environment Day and 22 April Earth Day. Honour 22 May.