Planets A and $B$ are uniform solid spheres that rotate at a constant speed about axes through their centers. Although B has twice the mass and three times the radius of $A,$ each planet has the same rotational kinetic energy. What is the ratio $\frac{{}_B}{{}_A}$ of their angular speeds?

$0\mathrm{.}165$

$0\mathrm{.}236$

$0\mathrm{.}191$

$0\mathrm{.}055$

$0\mathrm{.}093$