3. Let $z$ be a complex number, the argument of $z+2$ is $\frac{\pi}{3}$, and the argument of $z-2$ is $\frac{5 \pi}{6}$. Then $z$ equals ( ).
(A) $-\sqrt{3}+i$
(B) $-1+\sqrt{3} i$
(C) $-\frac{\sqrt{3}}{2}+\frac{1}{2} i$
(D) $-\frac{1}{2}+\frac{\sqrt{3}}{2} i$