It is A. Those are all decomposers, the other answers like C are all animals. Decomposers are are biotic organisms that break down basically dead plants or animals.
Take a White Flower and measure it with different soil temperatures and see if it changes colors. And don't forget to record the color and take a picture with different temperatures
A light year is the distance traveled by light in a year.
A.vibrates with the frequency of the received sound
