It Is Clear That a Heavy Dose of Pesticides or Other

It is clear that a heavy dose of pesticides or other toxic pollutants can kill species. However, chronic exposure to pollutants seems to cause recent high mortality in marine mammals by

A) Decreasing the plants that are normally in their environment, such as kelp, that they use for shelter
B) Killing off the prey species that they depend on for food
C) Direct bioaccumulation of the chemicals, such as lead, in their tissues
D) Causing weakened immune systems and increased vulnerability to infection
E) Eventually killing them