An open box with a square base is to be made out of a given quantity of cardboard of area c2 square units. The maximum volume of the box is
1
\(\frac{c^3}{6\sqrt{3}}\)
2
\(\frac{c^3}{3\sqrt{3}}\)
3
\(\frac{c^2}{6\sqrt{3}}\)
4
\(\frac{c^2}{6\sqrt{6}}\)