Find an Equation of the Circle with the Given Center $\frac { x ^ { 2 } } { 144 } + \frac { y ^ { 2 } } { 324 } = 1$

Multiple Choice

Find an equation of the circle with the given center and radius.
-A bridge with a semi-elliptical arch extends over a river as shown. Find an equation of the ellipse that represents the arch of the bridge.

A) $\frac { x ^ { 2 } } { 144 } + \frac { y ^ { 2 } } { 324 } = 1$
B) $\frac { x ^ { 2 } } { 144 } + \frac { y ^ { 2 } } { 81 } = 1$
C) $\frac { x ^ { 2 } } { 81 } + \frac { y ^ { 2 } } { 144 } = 1$
D) $\frac { x ^ { 2 } } { 324 } + \frac { y ^ { 2 } } { 144 } = 1$