Find the Least Common Denominator $\frac { 1 } { r ^ { 2 } + 10 r + 25 } - \frac { 1 } { r ^ { 2 } + 5 r }$

Multiple Choice

Find the least common denominator.
- $\frac { 1 } { r ^ { 2 } + 10 r + 25 } - \frac { 1 } { r ^ { 2 } + 5 r }$

A) $( r + 5 ) ^ { 2 }$
B) $r ( r + 5 ) ^ { 2 }$
C) r(r + 1) (r + 5)
D) r(r + 5)