The wording of the question is as follows:
You’re troubleshooting a refrigerator where both compartments are warm. Which one of the four main systems would you focus on first to confirm whether or not it’s working correctly?
Since both of the compartments are warm, you want to look at something that’s common to both of them. Each compartment has a different door seal, so that’s less likely to be a problem.
Which of the possible answers do you think would cause both compartments to warm?