Find an Interval For $\theta$ For Which the Graph Is Traced Only Once

Multiple Choice

Find an interval for $\theta$ for which the graph is traced only once.
$$r = 2 \sin \left( \frac { 3 \theta } { 2 } \right)$$

A)
$0 \leq \theta < \frac { \pi } { 3 }$
B)
$0 \leq \theta < \pi$
C)
$0 \leq \theta < 4 \pi$
D)
$0 \leq \theta < \frac { 4 \pi } { 3 }$
E)
$- 2 \pi \leq \theta < 2 \pi$