AMC 12A 2020 Problem 10

There is a unique positive integer n such that

\log _{2}\left(\log _{16} n\right)=\log _{4}\left(\log _{4} n\right) .

What is the sum of the digits of n ?

Answer Choices
A. 4
B. 7
C. 8
D. 11
E. 13