Answer
$$\lim_{\theta\to0}\theta\cos\theta=0$$
Work Step by Step
$$\lim_{\theta\to0}\theta\cos\theta=0\times\cos0=0\times1=0$$
In this exercise, we only need to replace $\theta=0$ into the function to find its limit as $\theta\to0$, because unlike the other ones, there is no version of $A/0$ or $A\times(\infty)$ as we replace $\theta=0$.