​Write the Partial Fraction Decomposition of the Rational Expression $\frac { 9 } { x ^ { 2 } + 16 x + 63 }$

Multiple Choice

​Write the partial fraction decomposition of the rational expression. $\frac { 9 } { x ^ { 2 } + 16 x + 63 }$

A) ​ $\frac { 9 } { 2 } \left( \frac { 1 } { x + 9 } - \frac { 1 } { x + 7 } \right)$
B) ​ $\frac { 9 } { x ^ { 2 } + 16 x + 63 }$
C) ​ $\frac { 9 } { x ^ { 2 } } + \frac { 9 } { 16 x } + \frac { 1 } { 7 }$
D) ​ $\frac { 9 } { 2 } \left( \frac { 1 } { x - 7 } - \frac { 1 } { x - 9 } \right)$
E) $\frac { 9 } { 2 } \left( \frac { 1 } { x + 7 } - \frac { 1 } { x + 9 } \right)$