Solve the Problem $$f ( x ) = \frac { 1 } { 7 x }$$

Multiple Choice

Solve the problem.
- $$f ( x ) = \frac { 1 } { 7 x }$$

A) $\frac { - 1 } { 7 x ( x + h ) }$
B) $\frac { 1 } { 7 x }$
C) 0
D) $\frac { - 1 } { x ( x + h ) }$