Find a Cartesian Equation for the Line Whose Polar Equation $\mathrm { r } \cos \left( \theta + \frac { \pi } { 4 } \right) = 5 \sqrt { 2 }$

Multiple Choice

Find a Cartesian equation for the line whose polar equation is given.
- $\mathrm { r } \cos \left( \theta + \frac { \pi } { 4 } \right) = 5 \sqrt { 2 }$

A) $y = x + 5 \sqrt { 2 }$
B) $y = x - 10$
C) $y = \sqrt { 2 } x - 10$
D) $y = x + 5$