Melanie recorded observations on the effect of two new fertilizers on the growth of plants. three identical plants having a height of 15 cm were used for the experiment. no fertilizer was added to the first plant, 100g of fertilizer a was added to the second plant, and 100 g of fertilizer b was added to the third plant. all other growing conditions of the plants were kept constant. which step of the scientific method did melanie do here?
a. drawing a conclusion
b. testing with an experiment
c. analyzing experimental data