To find the answer you have to do 7-3 to find out how many hours there were for the temperature to change.
7-3=4
So it took four hours so you have to do 4 times 2 but since the temperature is dropping you have to do 4 times negative 2 so
4x-2=-8
So then you have to subtract 8 from your original number which is 4, so
4-8=-4
So the ANSWER IS D (-4 degrees F)