An Accidental Spill of a Pesticide Locally Wiped Out the Most

Multiple Choice

An accidental spill of a pesticide locally wiped out the most abundant species of butterfly in coastal California.Most of the bird species in the area had fed on this butterfly,but they switched prey to moths,and thus the birds showed only a small decrease in population size.The butterflies were a/an:

A) keystone species, and thus they were driven to extinction very easily.
B) endangered species.
C) ecological dominant, but they were not a keystone species.
D) pioneer species.