It can't be any answer with cubed in it because that would be volume. So, A and C magically vanish. If we know that the length of a cube is w that means that all sides are w. There are six faces on a cube. If we want to find surface area we will have to add up the area of all faces. the area of one face will be w^2. We multiply that number by six and we get 6w^3.
