Solve
-The Planets in a Certain Solar System Have a Path

Multiple Choice

Solve.
-The planets in a certain solar system have a path that is an ellipse, with Star A as one of the foci. Planet $X$ has a perihelion of 588.6 million miles and an aphelion of 631.8 miles. Find an equation for Planet X's orbit. Express your answer with $a$ and $b$ in millions of miles, rounded to the nearest tenth of a million.

A) $\frac{x^{2}}{610.2^{2}}+\frac{y^{2}}{609.8^{2}}=1$

B) $\frac{x^{2}}{609.2^{2}}+\frac{y^{2}}{610.8^{2}}=1$

C) $\frac{x^{2}}{610.8^{2}}+\frac{y^{2}}{609.2^{2}}=1$

D) $\frac{\mathrm{x}^{2}}{609.8^{2}}+\frac{\mathrm{y}^{2}}{610.2^{2}}=1$