The Average case and worst case complexities for Merge sort algorithm are

A

$$O(n^{2}),O(n^{2})$$

B

$$O(n^{2}),O(n \log_{2} n)$$

C

$$O(n \log_{2}n),O(n^{2})$$

D

$$O(n \log_{2}n), O(n \log_{2}n)$$