Choices:
A). omnivores.
B). harmed.
C). deadly.
D). dead.
E). haploid.
F). negative.
G). dormant.
H). inactive.
Q: You are presented with the quiz "Ecology studies something that decreases when an animal species is what?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "harming an animal species causes that animal 's population to decrease" and "ecology is the study of populations or communities". So, what's the best answer to the question?
A:
B).