Hello there,
So obviously if your GPA is low, you should write “No”. In the explanation, you can also write why. But don’t make excuses! You can give reasons though (you were working two jobs, you were sick for a year, you were on a sports team, etc.), it will also be helpful if you have other ways to PROVE you are very smart (like a great GMAT or other test… or whatever else you can find)