One of the ways that you can check your work is to try turning the answer back into the original expression.

For choice B, raise the 2vw^2 to the power of 3.

(2vw^2)^3 = 8v^3w^6

When you move that back inside the cube root you get the cube root of 24v^3w^6, which is not the same as the original expression. You're still missing another w^2, which is why that appears in answer C.

Here's a video on simplifying roots that you may find helpful: https://www.khanacademy.org/math/algebra-home/alg-exp-and-log/alg-simplify-higher-index-roots/v/multiply-and-simplify-a-radical-expression-1

Thanks!