Final answer:
The question seeks a recursive call tree for QuickSort given a list of numbers; however, without knowing the pivot selection method, the exact tree cannot be determined. The tree would visualize the algorithm's recursive calls as a binary tree structure.
Step-by-step explanation:
The question asks for a visual representation of recursive calls made by the QuickSort algorithm when sorting a given list of integers. QuickSort picks an element as a pivot and partitions the given array around the pivot point. The process is repeated recursively for subarrays on both sides of the pivot. However, drawing this out involves choosing pivots and visualizing a tree of recursive calls. Since the exact pivot points are not provided, we can assume the first or last element of the sublist is chosen as the pivot in a typical QuickSort implementation.
Unfortunately, without the specific implementation details of Algorithm 2.6 referenced in the question, we cannot provide the exact recursive call tree. The tree diagram would resemble a binary tree where each node represents a call to QuickSort on a subarray, with branches depicting recursive calls on the partitions. This diagram would help understand the algorithm's depth and the sequence of recursive calls leading to the sorted array.