In an area where DDT had been used extensively, the population of birds declined significantly because:

Options

A. Birds stopped laying eggs
B. Earthworms in the area got eradicated
C. Cobras were feeding exclusively on birds
D. Many of the birds eggs laid, did not hatch

Answer

D

Explanation

Since the toxic effect of chemical is increases at each tropic level and found maximum it top consumers i.e. birds as a result many of the birds eggs laid did not hatch.