C because we are testing the effectiveness of Fertilizer X and Y and using no fertilizer can help determine if that would be better than using a fertilizer. Additionally, a control group of no fertilizer would be the third plant as that is considered normal for the experiment. Msg me for any more questions
Answer:
coal
Explanation:
I need 20 characters so Im typing this in hope of filling the space
I can’t see it it’s too blurry
