Process by which insecticides like DDT reach man is

The correct option is A Biomagnification
Bioaccumulation
Bioaccumulation is a process by which chemical substances like pesticides get accumulated in the body of an organism.

Biomagnification
Biomagnification refers to the phenomenon of increase in the accumulation of toxic substances within organisms at each successive level of the food chain.

Bioremediation
Bioremediation is the technique of treatment of contaminated soil or water by the use of microorganisms.

Eutrophication
Eutrophication is the natural ageing process of water bodies occurring due to the enrichment of the water by nutrients like nitrogen and phosphorus.

Final answer:
(B) Biomagnification