Answer:
A record is kept of all edits that are made so conflicts can be resolved.
Explanation:
If only primary coauthor's changes were retained, what will be the meaning of keeping multiple authors only board? However, other authors' changes cannot be finalized without the approval of the primary author. Though the record of all the edits can be kept, each edit is important and must be taken into account while finalizing the final document. And this way we can resolve the conflicts. Hence, the third option is the correct option, for this question.
