If $f ( x ) = x ^ { 2 } - x + 6$

Multiple Choice

If $f ( x ) = x ^ { 2 } - x + 6$ , evaluate the difference quotient $\frac { f ( a + h ) - f ( a ) } { h }$ .

A) $2 a + h - 6$
B) $2 a - 6$
C) $2 a - h - 6$
D) $h$
E) none of these