The correct option is A Biofertilizers
Through the use of biofertilizers, healthy plants can be grown, while enhancing the sustainability and the health of the soil. ... Biofertilizers such as Rhizobium, Azotobacter, Azospirilium and blue green algae (BGA) have been in use a long time. Rhizobium inoculant is used for leguminous crops. So, the correct option is "B" (Biofertilizers).