Find the Center of Mass of a Thin Plate of Constant

Multiple Choice

Find the center of mass of a thin plate of constant density covering the given region.
-The region cut from the first quadrant by the circle $x ^ { 2 } + y ^ { 2 } = 49$

A) $\bar { x } = 0 , \bar { y } = \frac { 28 } { 3 \pi }$
B) $\bar { x } = \frac { 7 } { 2 } , \bar { y } = \frac { 7 } { 2 }$
C) $\bar { x } = \frac { 7 } { 3 \pi } , \bar { y } = \frac { 7 } { 3 \pi }$
D) $\bar { x } = \frac { 28 } { 3 \pi } , \bar { y } = \frac { 28 } { 3 \pi }$