Personification. This is when someone gives human characteristics to something that will normally not have them, like in your case, fog slowly creeping by, which fog can't normally do.
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."
A vigorous, light or playful composition , typically comprising a movement in a symphony or sonata
I believe C is your best bet :) Good Luck
