A carpenter is putting a skylight in a roof. If the roof measures 10 + 8 by 8 + 6 and the skylight measures + 5 by 3 + 4, what is the area of the remaining roof after the skylight is built?
a. 77^2 + 115 + 68
b. 77^2 + 105 + 28
c. 83^2 + 115 + 68
d. 77^2 − 105 + 28