Answer:
D. Pool temperature
Step-by-step explanation:
The dependent variable in an experiment is the variable that is measured or responds to another variable called the independent variable. The outcome of the dependent variable is dependent on the independent variable.
In this computer model, the engineers compare which of several pool designs require the least amount of energy to be heated. The TEMPERATURE at which each pool design is heated is dependent on the type of pool design used. Hence, POOL TEMPERATURE is the dependent variable. It is the variable being measured in response to the type of pool design used.