The Polar Equation That Corresponds to the Rectangular Equation $x ^ { 2 } + y ^ { 2 } = 7 x$

Multiple Choice

The polar equation that corresponds to the rectangular equation $x ^ { 2 } + y ^ { 2 } = 7 x$ is

A) $r = 7 \sin \theta$
B) $r = - 7 \sin \theta$
C) $r = \frac { \pi } { 4 }$
D) $r = - 7 \cos \theta$
E) $r = 7 \cos \theta$