A company is constructing an open-top, square-based, rectangular metal tank that will have a volume of 46.5ft^3. What dimensions yield the minimum surface area?
a. 4.5 ft times 4.5 ft times 2.3 ft
b. 5.2 ft times 5.2 ft times 1.7 ft
c. 36 ft times 3.6 ft times 3.6 ft
d. 9.6 ft times 9.6 ft times 0.5 ft