A copper sphere $0\mathrm{.}3$ m in diameter radiates power through a vacuum to an environment at $273$ K $.$ The emissivity of copper is $0\mathrm{.}5,$ and the sphere is at $\backslash (60^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash ).$ The radiation emitted is most nearly

$28$ W

$30$ W

$37$ W

$53$ W