Answer:
Fertilizers
Explanation:
The independent variable is the variable that is manipulated or changed to trigger a change on the dependent variable. The dependent variable is the variable that is not manipulated, but it changes depending on the independent variable. In the case of this experiment, the scientists wanted to see if the different fertilizers have an effect on pea plants' growth. To determine this, they would have to use different types of fertilizers, so this meanst hat the fertilizers will be changed.
