Final answer:
Sets are the elements from the given options that do not have a positional order within the collection. An organizational chart or tree, heaps, and graphs all imply some level of structured arrangement or positional order.
Step-by-step explanation:
The elements that do not have positional order within the collection are sets. In mathematics and computer science, sets are defined as collections of distinct objects, known as elements or members, where the order of these elements is not relevant. This is in contrast to lists or sequences where the order of elements does matter. Sets are used to represent the concept of a group of items where one might care only about which items are included, and not about the sequence in which they are included.
An organizational chart or a tree has a clear hierarchical structure, which implies a positional order. A heap is a specialized tree-based data structure that satisfies the heap property, which also implies a specific arrangement of elements, although the order might be partial rather than absolute. In the context of a graph, while the position of nodes is not strictly ordered, they are defined by their connections to other nodes through edges, which implies some level of structured arrangement, even if it's not linear.