Answer: Option B
:
B
Nitrogen fixing microbes are including cyanobacteria, bacteria and fungi have the ability to fix atmospheric nitrogen into its uasable form that can be used by plants. Mycorrhiza is a fungi that is in a symbiotic association with the roots of plants. The fungal symbiont helps in solubalisation of inorganic phosphate in the soil and passes it to the plant. Rhizobia is a symbiotic nitrogen fixing bacterium which fixes nitrogen in roots of leguminous plants. Bacillus thuringiensis is a bacteriumwitha gene of insecticidal property.This gene has been inserted into the genome of different plants through the process of genetic engineering, most notably into the cotton genome to give rise to Bt-cotton. Now the plant can kill insects on its own without the use of pesticides.