Solve the Problem $\mathrm { r } = \frac { \mathrm { a } \left( 1 - \mathrm { e } ^ { 2 } \right) } { 1 + \mathrm { e } \cos \theta }$

Multiple Choice

Solve the problem.
-Given that the polar equation $\mathrm { r } = \frac { \mathrm { a } \left( 1 - \mathrm { e } ^ { 2 } \right) } { 1 + \mathrm { e } \cos \theta }$ models the orbits of the planets about the sun, estimate the closest approach of a planet for which $\mathrm { a } = 39$ and $\mathrm { e } = 0.78$ to the sun.

A) 9 astronomical units
B) 15 astronomical units
C) 4 astronomical units
D) 69 astronomical units