Find a Polar Equation of the Conic with Its Focus $( 10 , \pi / 2 )$

Multiple Choice

Find a polar equation of the conic with its focus at the pole. ​
Conics
Vertex or vertices
Parabola $( 10 , \pi / 2 )$ ​

A) $\frac { 20 } { 1 - \sin \theta }$
B) $\frac { 20 } { 1 + \sin \theta }$
C) $\frac { 20 } { 1 - \cos \theta }$
D) $\frac { 20 } { 1 + \cos \theta }$
E) $\frac { - 20 } { 1 - \sin \theta }$