A rectangle has a length of 18 units and a width of 7 units. Squares of ( w ) by ( w ) units are cut out of each corner, and then the sides are folded up to create an open box. Express the Volume ( V ) of the box [Select the correct answer below]:
a) ( V = w(18-2w)(7-2w) )
b) ( V = 18w - 2w² + 7w - 2w² )
c) ( V = 4w³ - 50w² + 126w )
d) ( V = 126w - 50w² + 4w³ )