Perform the Indicated Operation $\frac { 27 } { x ^ { 2 } - 4 x - 21 } - \frac { 4 } { x ^ { 2 } - 6 x - 7 }$

Multiple Choice

Perform the indicated operation. $\frac { 27 } { x ^ { 2 } - 4 x - 21 } - \frac { 4 } { x ^ { 2 } - 6 x - 7 }$

A) $\frac { 23 x + 15 } { ( x - 7 ) ( x + 3 ) ( x - 1 ) }$
B) $\frac { 23 x + 15 } { ( x - 7 ) ( x + 3 ) ( x + 1 ) }$
C) $\frac { 23 x + 15 } { ( x - 7 ) ( x - 3 ) ( x + 1 ) }$
D) No correct answer.