This is a hard one and I can see why you decided to post it here. B is most definitely wrong but the other three are all neck and neck. There are both even pros and cons of A and C but I think it would be more reasonable to adopt a general routine. So I think the answer would be C.
Answer:
the small Chihuahua defended her territory.
Explanatio
I just took the test or question thing and B and D are correct.