Answer:
OMG U HAVE THIS SAME QUESTION, I HAD THIS YESTERDAY, AND I KNOW WHAT IT IS.
Step-by-step explanation:
the son bought a candle and a match, when he lights up the candle, the light of the candle will fill the whole room. this riddle is not meant to fill the whole entire room with something, u an fill it up with something small. like the light in this case.