For part (i), the sort() function modifies the list in-place because lists are mutable, arranging elements in ascending order. In part (ii), sorted() returns a new sorted list but does not change the original list object; since the return value isn't stored, printing list1 shows the original unsorted list. For part (iii), list1[:3] extracts the first three elements and list1[3:] extracts elements from index 3 to the end; the + operator concatenates them back into the original sequence. In part (iv), len(list1) is 5, so the index accessed is 4, which refers to the last element.