Find the Area of the Region Specified by the Integral(s) $$\int _ { 0 } ^ { 9 } \int _ { 0 } ^ { 9 - x } d y d x$$

Multiple Choice

Find the area of the region specified by the integral(s) .
- $$\int _ { 0 } ^ { 9 } \int _ { 0 } ^ { 9 - x } d y d x$$

A) $\frac { 81 } { 4 }$
B) 27
C) $\frac { 81 } { 2 }$
D) $\frac { 27 } { 2 }$