If You Were Going to Study the Effects of a Certain

Multiple Choice

If you were going to study the effects of a certain fertilizer on plant growth, which list of variables would you most likely want to control (keep constant) ?

A) Plant type, soil type
B) Plant type, soil type, water, light
C) Plant type and fertilizer
D) Fertilizer, soil type, water, light
E) Fertilizer, soil type , water, plant type