An Open Box Is to Be Made from a Square $V ( x ) = - 2 x ^ { 3 } + 28 x ^ { 2 }$

Multiple Choice

An open box is to be made from a square piece of cardboard,28 inches on a side,by cutting equal squares with sides of length x from the corners and turning up the sides (see figure below) .Determine the function,V,in terms of x,that represents the volume of the box.

A) $V ( x ) = - 2 x ^ { 3 } + 28 x ^ { 2 }$
B) $V ( x ) = - 4 x ^ { 3 } + 56 x ^ { 2 }$
C) $V ( x ) = 4 x ^ { 3 } - 56 x ^ { 2 } + 28 x$
D) $V ( x ) = - 4 x ^ { 3 } + 56 x ^ { 2 } - 28 x$
E) $V ( x ) = 4 x ^ { 3 } - 112 x ^ { 2 } + 784 x$