Find the LCD of the Given Rational Expressions $$\frac { 8 } { 9 x + 36 } , \frac { 3 } { x ^ { 2 } + 4 x }$$

Multiple Choice

Find the LCD of the given rational expressions.
- $$\frac { 8 } { 9 x + 36 } , \frac { 3 } { x ^ { 2 } + 4 x }$$

A) $9 x ( x + 4 )$
B) $9 x + 4$
C) $9 x ^ { 2 } + 36$
D) $9 x ^ { 2 } + 4$