5. Kevin wanted to determine the effect of fertilizer on plant growth. He purchased 9 identical plants and separated them into 3 groups. Group 1 did not receive fertilizer, Group 2 received one teaspoon of fertilizer, and Group 3 received two teaspoons of fertilizer. All the plants received the same amount of water and were placed in the same location so they could receive the same amount of sunlight. What was the outcome variable (dependent variable) in Kevin's experiment? A. the type of plant B. the growth of the plant C. the amount of fertilizer D. the amount of sunlight​