For prisms, use the formula: 2B + Ph
B = base of figure, here it is the trapezoid.
The area of the trapezoid is (3+6)*4/2 = 18
P = perimeter of the base, which is 3+4+5+6 = 18
h = height, here it is 5.
Thus the answer is:
2*18 + 18*5 = 36 + 90 = 126 cm^2
(C)