Solve the Problem for the Given Information $45 ^ { \circ }$

Multiple Choice

Solve the problem for the given information.
-Find the equation of a line passing through the origin and making a $45 ^ { \circ }$ angle with the positive $x$ -axis.

A) $y = \frac { \sqrt { 3 } } { 3 } x$
B) $y = \frac { \sqrt { 2 } } { 2 } x$
C) $y = x$
D) $y = - x$