Which sorting algorithm is used by .NET’s Array.Sort() method?

Array.Sort() chooses one of three sorting algorithm, depending on the size of the input:

1. If the size is fewer than 16 elements, it uses an insertion sort algorithm.
2. If the size exceeds 2 * log^N, where N is the range of the input array, it uses a Heap Sort algorithm.
3. Otherwise, it uses a Quicksort algorithm

Source: Array.Sort(Array) Method on MSDN.