Question 1

Here is an array which has just been partitioned by the first step of quicksort: `3, 0, 2, 4, 5, 8, 7, 6, 9` Which of these elements could be the pivot? *(Correction — the source paper printed two options, `5 and 4` and `5 or 4`, that denote exactly the same set of values, so neither could be chosen over the other. One of the two has been replaced with a distinct incorrect option so that this item