Posted this question twice ! somebody like i just need this last !

a box without a top is made from a rectangular piece of cardboard, with dimensions 12 cm by 10 cm, by cutting out square corners with side length x.

which equation can be used to determine the greatest possible volume of the cardboard box?

a. (12 - x) (10 - x)x = 0
b. (10 - 12x) (12 - 10x) = 0
c. (12 - 2x) (10 - 2x)x = 0
d. (12x - 10) (10x - 12) = 0