A biodegradable insecticide has been obtained from.

Answer is option C i.e. "Marigold"
Biodegradable insecticides are types of insecticides derived from natural materials as plants, bacteria, etc. Bioinsecticide from marigold flowers contains chemicals called thiophenes which are toxic to the larvae of mosquitoes that carry malaria and yellow fever. Bioinsecticide made from marigold also contains repellent against major tomato pests: whiteflies, thrips, and spider mites.