6. Given the function $f(x)=2 \sin x-\sin 2 x+\sqrt{3}$, which of the following statements is incorrect?
A. $f(x)$ has two zeros in $[-\pi, \pi]$
C. The minimum value of $f(x)$ is $-\sqrt{3}$
B. The graph of $f(x)$ is symmetric about the point $(\pi, \sqrt{3})$
D. The maximum value of $f(x)$ is $\frac{5 \sqrt{3}}{2}$