Fill in a brief comment if you answer "no" or "n/a." Ignore the comment boxes when you answer yes. After you have filled in the form, go to the bottom, save it, then click on the box at the bottom that allows you to check if everything is answered. If you need to add more info to any of the comment boxes, they will be outlined in red. Keep checking and answering until none of the boxes is red anymore.
Sometimes the MS company will specify that they want a certain percentage of the boxes to have comments. Be sure to check the guidelines, as they supercede all. Good luck.