Given two complex numbers $z=3-3j,$ and $w=1+7j,$ which of the following options equals $\frac{z}{w}?$

$-\frac{18}{50}-\frac{24}{50}j$

$-\frac{18}{50}+\frac{24}{50}j$

$-\frac{18}{\sqrt[\phantom{2}]{50}}+\frac{24}{\sqrt[\phantom{2}]{50}}j$

$-\frac{18}{\sqrt[\phantom{2}]{50}}-\frac{24}{\sqrt[\phantom{2}]{50}}j$