Which of the following ecosystems is most productive in terms of net primary production?

1. Deserts

2. Tropical rain forests

3. Oceans

4. Estuaries

Ans. (b) In terms of net primary productivity, the tropical rain forest is at the top followed by coral reet, estuaries, and desert and ocean. Thus option 'b is correct while 'a, 'c, and 'd' are wrong.