A. building tables,
because I'm not sure how that will exactly help you in studying. However, in my opinion, the other three seem able to work.
Sorry if this answer is kind of late, but this is the first time in ages since I've logged on. Have a good night and life though! :3
I believe it's "Each change of speaker" because punctuation marks always go inside quotation marks.
It is C Emphasis .............
