Which of the following is the correct factored form of x2−6x+9x^2 - 6x + 9x2−6x+9?
(x−9)(x+1)(x - 9)(x + 1)(x−9)(x+1)
(x+3)2(x + 3)^2(x+3)2
(x−3)2(x - 3)^2(x−3)2
(x−3)(x+3)(x - 3)(x + 3)(x−3)(x+3)