Biomagnification is the buildup of certain pollutants, such as DDT, in the bodies of organisms at higher trophic levels in the food chain. The concentration of a pollutant increase from one link to another. Organisms at lower trophic levels accumulate small amounts. It occurs because a pollutant has low or non-existent rate of internal degradation or excretion. Organisms at the next higher level eat many of these lower-level organisms and hence accumulate larger amounts, especially in fatty tissues. Thus, the highest biomagnification is at the highest level in the food chain and the correct answer is B) Secondary consumers.