Answer:
In this setting of the experiment, where Chloe wants to find if rooting hormone is advantageous or detrimental in this process. There are too many variables present in her experiment. These variables would affect the experiments.
She wanted to test the rooting hormone is a variable of interest. She also had a dome over the cuttings and set them in direct sunlight as variables. She can improve the experiment design by replicated the conditions of the control group.