Chapter 8 - Complex Numbers, Polar Equations, and Parametric Equations - Section 8.5 Polar Equations and Graphs - 8.5 Exercises - Page 389: 44

$r = \frac{2}{cos~\theta+sin~\theta}$ This equation matches up with graph B.

$r = \frac{2}{cos~\theta+sin~\theta}$ This equation is an equation of a straight line. Note that $r=2$ when $\theta = 0^{\circ}$ and when $\theta = 90^{\circ}$. This equation matches up with graph B.