D. radiant
Light energy isnt nuclear because nuclear means explosive we use light for lots of things and it doesnt explode! chemical the sun is light but it is too hot to reach it and study it so it cant be formed or made gravitational means gravity light doesnt make everything like you on the moon nor makes you feel like you have an elephant on your back radiant is hot and bright and one example is the sun it provides warmth and light so people can see.
hope this helps!