Select the equivalent expression.


\[\left(\dfrac{a}{ b^3}\right)^{4}=?\]
Choose 1 answer:
Choose 1 answer:
(Choice A)

\[\dfrac{a}{ b^{81}}\]
A

\[\dfrac{a}{ b^{81}}\]
(Choice B)

\[\dfrac{a^{5}}{ b^{7}}\]
B

\[\dfrac{a^{5}}{ b^{7}}\]
(Choice C)

\[\dfrac{a^{4}}{ b^{12}}\]
C

\[\dfrac{a^{4}}{ b^{12}}\]
(Choice D)

\[\dfrac{a^{8}}{ b^{8}}\]
D

\[\dfrac{a^{8}}{ b^{8}}\]

The equivalent expression to $\left(\dfrac{a}{ b^3}\right)^{4}$ is $\dfrac{a^{4}}{ b^{12}}$.

Therefore, the answer is $\boxed{\dfrac{a^{4}}{ b^{12}}}$.