I think the answer is D sorry if wrong
The outcome of a poorly written subject line would be that the reader wouldn't understand what he/she was reading about. This would in turn, keep the reader confused the rest of the literature and wouldn't be able to focus.
Dialogue can show the reader how the character thinks, interacts with others, communicates, and possibly even where the character is from and/or their educational level.
B so the answer I did this one