Liczba \sqrt[3]{ 7/3 } ⋅ \sqrt[3]{ 81/56 } jest równa

$\displaystyle \frac{\sqrt{3}}{2 }$\displaystyle \frac{\sqrt{3}}{2 }

$\displaystyle \frac{3}{2\sqrt[3]{21}}$\displaystyle \frac{3}{2\sqrt[3]{21}}

$\displaystyle \frac{3}{2}$\displaystyle \frac{3}{2}

$\displaystyle \frac{9}{4}$\displaystyle \frac{9}{4}