Let $f ( x ) = x ^ { 2 } - 9 x + 21$

Multiple Choice

Let $f ( x ) = x ^ { 2 } - 9 x + 21$ For what value(s) of x is $f ( x ) = 1$ ?

A) $x = 7 , x = 8$
B) $x = 8 , x = 9$
C) $x = 5 , x = 4$
D) $x = 6 , x = 7$
E) $x = 5 , x = 6$