Consider an array of length $n$ containing integer values.

Which of the following statements regarding the time complexity of the merge sort algorithm is true?

a$.$ Merge sort has a time complexity of $O(n)$ in all cases.

b$.$ Merge sort has a time complexity of $O(nlogn)$ in the worst$-$case scenario.

c$.$ Merge sort has a time complexity of $O(n^2)$ in the best$-$case scenario.

d$.$ Merge sort has a time complexity of $O(logn)$ in the average$-$case scenario.

Clear my choice