Meredith notices that different plant fertilizers are made up of different chemicals. some fertilizers are high in nitrogen. other fertilizers are high in phosphorus. meredith hypothesizes that nitrogen-rich fertilizers are best to grow fruit crops such as strawberries. when she is designing her experiment, what should be her variable? a. type of fruit crop b. amount of light given to plants c. type of fertilizer d. amount of water given to plants