Ican't find anyone who knows the answer to this!

a scientist sets up an experiment to see how colored lights affect the height of plant growth. he grows one group of plants in full sunlight, one group under red lights, one group under blue lights, and one group under green lights. all the plants are exactly that same type and all receive an equal intensity of life. at the end of the experiment he measures all the plants.

what is the independent and dependent variable in this equation?

(a) the color of the light

(b) the height of the plant

(c) sunlight

(d) the intensity of the light