Find the Distance from the Pole to the Directrix $$r = - \frac { 30 } { 15 + 31 \sin \theta }$$

Multiple Choice

Find the distance from the pole to the directrix for the conic $$r = - \frac { 30 } { 15 + 31 \sin \theta }$$

A) $\frac { 30 } { 31 }$
B) $\frac { 31 } { 30 }$
C) 30
D) $\frac { 31 } { 15 }$
E) 62