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.
Time
Transition words for time: after, then, finally
Answer:
I'd like to say it's dialogue as the other terms don't quite fit. I'm not 100% sure though.
Explanation:
