Which Sorting Algorithm does the following code represents?

public class XSort $\{$

public static void XSort$($int$[]$ arr, int begin, int end$)\{$

if $($begin $$ end$)\{$

int partitionIndex $=$ partition$($arr$,$ begin, end$)$;

XSort$($arr$,$ begin, partitionIndex$-1)$;

XSort$($arr$,$ partitionIndex $+1,$ end$)$;

$\}$

Quick Sort Algorithm

Bubble Sort

Selection Sort Algorithm

Merge Sort Algorithm