Find a Polar Equation for the Conic Described $( 3,0 )$

Multiple Choice

Find a polar equation for the conic described.
-The ellipse with a focus at the pole and major axis endpoints $( 3,0 )$ and $( 1 , \pi )$

A) $r = \frac { 3 } { 1 + \cos \theta }$
B) $r = \frac { 3 } { 2 + \sin \theta }$
C) $r = \frac { 3 } { 2 - \cos \theta }$
D) $r = \frac { 3 } { 2 + \cos \theta }$