Suppose your algorithm for sorting an array is to divide it in half, and take halves and divide them in half again, doing this until each piece has $1000$ elements. At this lowest division, selection sort is used to order those $1000$ elements. The parts are then merged together, all the way back up to the complete ordered array. What can be said about the performance of this algorithm for large arrays?

Question $9$ options:

The algorithm is the same order as the selection sort

The algorithm is the same order as the merge sort

The algorithm performs as the average of the two sorts

The algorithm is slower than either of the two sorts by themselves