Well, you don't exactly comment per se. You click "answer" or go to someone else's answer and click reply (not sure the exact labelling but it's something along those lines).
Edit: It says "add your comment to this answer here", not "reply."
I believe the answer is letter D. This being the only one that seems to relate best with the topic sentence.
Thane of Glamis, Thane of Cawdor, and King
A lot of words. No one can’t name all of them.