ANSWER:
[tex]B.\text{ }\sqrt[3]{n^2}[/tex]
STEP-BY-STEP EXPLANATION:
We have the following expression:
[tex]\left(\frac{1}{n}\right)^{\frac{-2}{3}}[/tex]
we can simplify to get the answer, like this:
[tex]\begin{gathered} a^{-b}=\frac{1}{a^b} \\ \\ \text{ Therefore:} \\ \\ \left(\frac{1}{n}\right)^{\frac{-2}{3}}=n^{\frac{2}{3}} \\ \\ n^{\frac{2}{3}}=\sqrt[3]{n^2} \end{gathered}[/tex]
Therefore, the correct answer is B.
