The use of a calculator is permitted. A cylinder has a volume of 400 cm³. Find the dimensions that minimize its surface area.
a) r = 7.368 cm, h = 7.368 cm
b) r = 5.848 cm, h = 11.696 cm
c) r = 4.642 cm, h = 9.283 cm
d) r = 14.142 cm, h = 2 cm