Suppose you are performing an experiment that is studying how different amounts of water giving to 3 separate plants impacts how tall each plant can grow The amount of water given to the plants can be described as

In your experiment, the amount of water given to the plants is best described as:

3. The independent variable

This is because the independent variable is the factor that you manipulate or change in an experiment to observe its effect on another variable—in this case, the height of the plants, which is the dependent variable.