Which one of the following is not a biofertilizer?

Using biofertilizers is a natural way of boosting the growth of plant tissues as they consist of living microorganisms which aids to the growth by filling up the nutritional gaps in plants.

Agrobacterium is not a biofertilizer but a gram negative bacteria which is responsible for the process of transformation, that is transfer of small DNA fragments into the plant genome.

Final Answer Hence, option A: Agrobacterium is the correct answer.