Ans: C
Consider $y=a\sin(x^\circ + \theta)$.
Consider $y=a\sin(x^\circ + \theta)$.
For $a>1$, $y=\sin x$ is enlarged along $y$-axis $a$ times.
For $\theta>0$, $y=\sin x$ is translated to the left $\theta$ units. For $\theta<0$, $y=\sin x$ is translated to the right $-\theta$ units.
Note that the $3$ $x$ intercepts of $y=\sin x^\circ$ are $0$, $180$ and $360$. The third $x$ intercept $360$ is translated to the left to $330$. Therefore, $\theta=30^\circ$.
