Because she is the "bad guy." Protagonist is good, antagonist is bad.
Answer:
i think the answer is B cause I've had this question before
The answer would be A: A labeled diagram of a car engine. This would show the viewers what each part is and where it goes in order to rebuild the engine.
I think the answer you are looking for might be B. Actually I don´t see how it could be D. I´m sure it´s B.