The correct option is D O(n log log n)
We will apply master theorem in this question:
a = 2, b = 2 and k = 1 and p =-1.
We will compare a and bk
i.e.,
2=21 and we have p = - 1
Then T(n)=⊝(nlog22log log n)
T(n)=⊝(n log log n)
and⊝(n log log n)>O(n log log n)
So, option (C) is correct.