Answer: Option D
:
D
Biofertilizersare defined as preparations containing living cells or latent cells of efficient strains of microorganisms that help crop plants uptake nutrientsdue to their interactions in the rhizosphere (narrow region of soil that is directly influenced by root secretions and associated soil microorganisms)when applied through seed or soil. Examples includeRhizobium, Nostoc etc.Mycorrhizais a fungi that is in a symbiotic association with roots of plants and it helps in absorption of phosphate from the soil. Agrobacterium is a gram negative bacterium that causes tumors in plants. It is well known for its ability to transfer DNA intoplantsand for this reason it has become an important tool for genetic engineering. A. tumefaciens causes crown-gall disease in plants. A. tumefaciens is therefore not a biofertilizer.