Which data structure allows for direct access to items by positional index in an ordered list?

The correct choice is the array, as it is a fundamental data structure that provides direct access to its elements using a positional index. In an array, elements are stored in contiguous memory locations, enabling efficient retrieval of values based on their index. For example, if you have an array of integers, you can access the first element by its index 0, the second element by index 1, and so on. This constant time complexity for access—O(1)—makes arrays particularly suitable for applications where quick retrieval is necessary.

In contrast with other data structures, while records (or structures) can store multiple fields of different types, they do not inherently provide a numeric index for direct positional access. Hash tables allow for fast retrieval but based on key-value pairs instead of a sequential index, which means access time is dependent on the hash function's effectiveness. Binary trees structure data hierarchically and require traversals to find elements, which does not allow for direct positional access based solely on an index. Thus, the array uniquely provides the ability to access items directly via a positional index in an ordered list, confirming its role in efficient data manipulation and retrieval.