How would you experiment to find out how much water this plant type needs for optimal growth

The correct answer will be- by providing different amount of water to experimental groups.

Explanation:

The scientific experimental samples are divided into two groups: the control group in which the variable to be studied is kept constant and the experimental variable to which different amount of studied variable is provided.

In the given question, the scientific question is how much amount of water is required for the optimal growth of the plants. The variable to be studied is water, so different amount of water is provided to different pots like 10 ml, 20 ml, 30 ml and so on.  So the plant which will respond best to this amount will be the optimal concentration of the water required by the plant to grow.

the dependant variable is spilled water

the independent is the heat