Answer:
d, the number of degrees that the temperature was lowered by
Explanation:
The dependent variable in this scenario would be d, the number of degrees that the temperature was lowered by. This is because the value of this variable depends on the actual amount of hours that have passed by. Therefore, depending on the number of hours, the value of d could be completely different. The variable h for the number of hours does not depend on any other variable in the equation and has its own value, but since d depends on h then it would be the dependent variable in this scenario.