Find the Distance from the Pole to the Directrix for the Conic

Multiple Choice

Find the distance from the pole to the directrix for the conic $$r = \frac { 42 } { 14 + \cos \theta }$$

A) $\frac { 1 } { 14 }$
B) 14
C) $\frac { 1 } { 42 }$
D) 42
E) 7