Answer: D. Biological magnification
Step-by-step explanation:
A food chain is a linear sequence of transfer of food and energy when one organism is consumed by another organism. The transmission of food and energy takes place from the lower trophic level to higher trophic levels when organisms of the lower trophic level are consumed by the organisms of higher trophic levels.
Biological magnification is a phenomena in which a toxic material or pollutant enters into the food chain. The material remains undigested in the body of the organisms and causes detrimental effects. The organisms at the highest trophic levels decline in number due to the increase in concentration of the toxic at the higher level as they consume organisms of the lower trophic levels.
According to the given situation, biological magnification is the correct option because here the amounts of pollution at the higher trophic levels is the greatest as compared to the lower trophic levels.