Express the complex number $z=-1-\sqrt[\phantom{2}]{3}i$ in polar form rcis$.$

Select the correct answer below:

$4$cis$\frac{5}{6}$

$4$cis$\frac{4}{3}$

$2$cis$\frac{}{3}$

$2$cis$\frac{4}{3}$

$4$cis$\frac{}{3}$

$2$cis$\frac{5}{6}$