9. Given the function
$$
f(x)=\sin \left(2 x-\frac{\pi}{6}\right)-m
$$

has two zeros in $\left[0, \frac{\pi}{2}\right]$. Then the range of $m$ is
(A) $\left(\frac{1}{2}, 1\right)$
(B) $\left[\frac{1}{2}, 1\right]$
(C) $\left[\frac{1}{2}, 1\right)$
(D) $\left(\frac{1}{2}, 1\right]$