Convert the Rectangular Equation to Polar Form $a > 0$ $y = - 7$

Multiple Choice

Convert the rectangular equation to polar form. Assume
$a > 0$
$y = - 7$

A) $r = - \csc \theta$
B) $r = - 7 \sec \theta$
C) $r = - 7 \csc \theta$
D) $r = - 7 \cos \theta$
E) $r = - 7 \sin \theta$