已知集合 $A=\left\{\sin \frac{7 \pi}{6}, \cos \frac{5 \pi}{3}, \tan \frac{5 \pi}{4}\right\}, B=\left\{-\frac{\sqrt{3}}{2},-\frac{1}{2}, 1\right\}$ ，则 $A \cap B=$
A. $\left\{-\frac{\sqrt{3}}{2},-\frac{1}{2}\right\}$
B. $\left\{-\frac{\sqrt{3}}{2}, 1\right\}$
C. $\left\{-\frac{1}{2}, 1\right\}$
D. $\left\{-\frac{\sqrt{3}}{2},-\frac{1}{2}, 1\right\}$