If the cardboard is 15 inches long and 8 inches wide, and the square cutaways have dimensions of ( x ) inches by ( x ) inches, find a function giving the volume of the resulting box.
a) ( V(x) = x(15 - 2x)(8 - 2x) )
b) ( V(x) = 15x - 8x² )
c) ( V(x) = 120x - 46x² )
d) ( V(x) = 2x³ - 23x² + 120x )