I would say that A is the answer. B is irrelevant, C makes the point debatable as it acknowledges that not everyone has access and I feel like A is more important than D to the sort of people who would set questions
Authors use DIALOGUE to portray characters and dramatize conflicts as well as give the readers a better understanding of the character and why they behave a certain way
I’m going to guess A I thought I took this test before.
True, depending on how a pronoun is used, it's case can change.