When a candle burns, you can't hear the flame, and you can't light a light-bulb with it, so you know that there's no sound energy or electrical energy coming from it.
However, if you've ever actually been around a candle while it's in the act of burning, you may have noticed that you can SEE the flame, and if you put your hand close enough to it, you can FEEL the flame and even burn yourself in it. These observations indicate that while the candle is burning, the chemical energy in it is being converted to light energy and heat energy. (choice-C)