The primary raw material used by the Assam Bio Refinery Private Limited is :

The correct answer is option 2. Key Points Assam Bio Refinery Private Limited uses water hyacinth as the primary raw material for producing bioethanol and other bio-based products. Water hyacinth is an invasive aquatic plant that has posed environmental challenges in Assam’s water bodies, and the refinery has found a way to use this plant for productive purposes. This innovation helps in environmental management while creating renewable biofuels.