A group of scientists are studying the effects of different fertilizers on the growth of pea plants. They began their study with 10 pea plants. They gave each plant a different type of fertilizer and tracked their growth over a period of 2 months. The results of this experiment weren’t considered valid by other scientists because there was no control group. Which of the following represents an appropriate control group for this experiment? A. A group of plants that’s subjected to two fertilizers B. A group of plants that’s subjected to one fertilizer C. A group of plants that’s not subjected to any fertilizer D. A group of plants that’s subjected to all types of fertilizers