Find the Volume Under the Surface Z = F(x,y) and Above

Multiple Choice

Find the volume under the surface z = f(x,y) and above the rectangle with the given boundaries.
-z = 8x + 4y + 7; R = {(x, y) : 0 $\le$ x $\le$ 1, 1 $\le$ y $\le$ 3}

A) 28
B) 26
C) 36
D) 38