Read the Scenario and Answer the Accompanying Questions

Multiple Choice

Read the scenario and answer the accompanying questions.
In the late 1800s the federal government began eradicating the grey wolf from Yellowstone because of fear that the wolf population would have a negative impact on the area's elk, which were considered a more desirable species at that time. The eradication of this keystone species continued until the 1930s, when wolves were effectively eliminated from the lower 48 states. In the absence of wolves, elk populations begin to explode and that, in turn, resulted in what has become known as a trophic cascade. Use this information to answer the following questions on the effects of keystone species eradication and the resulting trophic cascade.
-With an overabundance of elk, the next population in the Yellowstone ecosystem to be directly affected was/were _________.

A) songbird
B) mountain lion
C) plant species
D) wolves
E) beaver