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Where is the tangent line to the graph of the polar equation $r=1+\cos{\theta}$ vertical?

$\theta=0$ and $\theta=\pi$

$\theta=\cfrac{2\pi}{3}$ and $\theta=\cfrac{4\pi}{3}$

$\theta=0$, $\theta=\cfrac{2\pi}{3}$, and $\theta=\cfrac{4\pi}{3}$

There are no points where the tangent line is vertical.