Perform the Indicated Operation $$\frac { 3 x } { 13 } + \frac { 8 x } { 13 }$$

Multiple Choice

Perform the indicated operation. Simplify if possible.
- $$\frac { 3 x } { 13 } + \frac { 8 x } { 13 }$$

A) $\frac { 13 x } { 11 }$
B) $\frac { 11 x ^ { 2 } } { 13 }$
C) $\frac { 11 \mathrm { x } } { 26 }$
D) $\frac { 11 \mathrm { x } } { 13 }$