Answer
C. symmetry with respect to the x-axis
Work Step by Step
Whenever $(r, \theta)$ is on the graph, so is $(r, -\theta)$.
$x = r~cos~\theta = r~cos(-\theta)$
$y = r~sin~\theta = -r~sin(-\theta)$
Therefore, whenever $(x,y)$ is on the graph, so is $(x,-y)$.
Then the graph will have symmetry with respect to the x-axis.
