Find the value of $k$ in the following so that the function $f$ is continuous at the indicated point $f(x)=\left \{\begin{array}{1 1}\large\frac{1-\cos kx}{x\sin x}, & if\;x\neq 0\\\large\frac{1}{2}, & if\;x=0\end{array}\right.\;at\;x=0$

Question

$\begin{array}{1 1} -1 \\ 1 \\ \pm 1 \\ None\;of\;the \;above\end{array} $