Answer:
C.

Explanation:
We are asked to choose the expression, which has a value of 16, when n=5.
Let us check our options one by one by substituting n=5 in the given expressions.
A.

Upon substituting n=5 in our expression we will get,



As we got 12 from solving our expression, therefore, option A is not a correct choice.
B.

Upon substituting n=5 in our expression we will get,



As we got 15 from solving our expression, therefore, option B is not a correct choice either.
C.

Upon substituting n=5 in our expression we will get,



As we got 16 from solving our expression, therefore, option C is the correct choice.
D.

Upon substituting n=5 in our expression we will get,



As we got 11 from solving our expression, therefore, option D is not a correct choice.