As for this problem concerning about the writing process, the most probable and the most likely answer to this would be D. publishing.
The final step in the writing process is publishing. This would be the final since after this, there would be no more revisions and correcting of mistakes, adding of ideas or anything, changes would be not considered anymore. Of the options presented, drafting would come first, followed by editing, then revising. Publishing would be the decision where there is no going back.