Zach is conducting an experiment to observe which type of fertilizer will allow a plant to grow the tallest. he put three plants in identical pots and placed them in the same location. He watered the plants each day with the same amount of water. Next, Zach measured the plant growth and then recorded his observations. Which of these is the Test (independent) variable in Zach's experiment?

What is the best conclusion based on this data? the hypothesis was not supported because the data indicated that fertilizing plants does not improve plant growth. the hypothesis was supported; to get the best growth, use 5 milliliters of fertilizer per plant. the hypothesis was not supported; the data indicated that too much fertilizer can inhibit plant growth. the hypothesis was supported; to get the best growth, use 15 milliliters of fertilizer per plant.