The correct answer is "[tex]O (n\times Log n)[/tex]". A further explanation is given below.
Explanation:
Throughout all the three instances (worst, average as well as best), the time complexity including its Merge sort seems to be [tex]O (n\times Log n)[/tex] as the merge form often splits the array into two halves together tends to linear time to combine multiple halves.
As an unsorted array, it needs an equivalent amount of unnecessary capacity. Therefore, large unsorted arrays are not appropriate for having to search.
