Ans is A.
In these type questions where √ is given take n= 2^m
so, √ n =2^(m/2)
now substitute the respective powers of n for m
T(m) =T(m/2) + logm
Solving by Master's Theorem u get-->
log m * log m
now replacing m by log n (since n= 2^m) we get
θ (log log n) ^2 as ans..