Solve $x ^ { 2 } - 6 x + 9 = 0$

Solve $x ^ { 2 } - 6 x + 9 = 0$ by factoring.

A) $x = 3 , x = - 3$
B) x=3
C) x=-3
D) $x = 0 , x = 3$
E) $x = 3 , x = \frac { 3 } { 2 }$