#### Answer

a. $r=\frac{4}{1-sin\theta}$
b. $e=1$, $p=4$, parabola.
c. see figure.

#### Work Step by Step

a. The equation, $r=\frac{4}{1-sin\theta}$, is already in the standard form of a conic in polar coordinates.
b. From the above equation, we can determine $e=1$ and $ep=4$, which gives $p=4$. With $e=1$, the equation can be identified as a parabola.
c. We can graph the polar equation as shown in the figure.