The reson that the chemical/synthetic fertilisers should be replaced by biofertilisers is that the former

Options

A. are source of environmental pollution
B. are expensive
C. axaust the valuable energy resources for their manufacture
D. all of these

Answer

D

Explanation

Chemical fertilisers are being used in increasing amounts in order to increase output in high yielding varieties of crop plants. However, chemical fertilisers cause pollution of water bodies as well as ground water, besides getting stored in crop plants. They are expensive and also require lot of energy resources in their manufacture.