Biomagnification of toxic substances means that _____________
A. organisms higher in the food web are more sensitive to a given concentration of toxic substances within their tissues
B. molecules of the toxic compounds grow larger and form crystals after they accumulate in the tissues of marine animals
C. the presence of a toxic substance strengthens the immune systems of organisms higher in the food web
D. toxic substances become increasingly concentrated in the tissues of organisms in each higher level of the food web
E. larger organisms are not affected by the toxic substances, but they suffer stress when their prey such as plankton are killed off