ANSWER:
D.
[tex]r\cos \theta=2[/tex]
STEP-BY-STEP EXPLANATION:
We have a graph that is a vertical on a polar coordinate plane.
That is, the equation would be:
[tex]\begin{gathered} x=\text{ constant} \\ \text{ in this case:} \\ x=2 \end{gathered}[/tex]
We know that the value of x, in polar coordinates, is as follows:
[tex]\begin{gathered} x=r\cdot\cos \theta \\ \text{ therefore:} \\ r\cos \theta=2 \end{gathered}[/tex]
