Find the Polar Equation for the Curve Represented by the Given

Multiple Choice

Find the polar equation for the curve represented by the given Cartesian equation. Select the correct answer.
$x + y = 2$

A) $r = 2 ( \cos \theta + \sin \theta )$
B)
$r = \frac { 1 } { \cos \theta - \sin \theta }$
C)
$r = \frac { 2 } { \cos \theta + \sin \theta }$
D)
$r = \frac { 2 } { \cos \theta - \sin \theta }$
E) $r = 1 ( \cos \theta + \sin \theta )$