Which of the following statements about dictionaries is true?

Dictionaries in Python are indeed designed to store values in key-value pairs. This means that each key is unique within the dictionary and is used to access the associated value. The key acts as an identifier, making it possible to retrieve the corresponding value efficiently. This characteristic of dictionaries is fundamental to how they operate, allowing for fast lookups and organized data management.

In contrast, dictionaries do not allow for duplicate keys, meaning each key must be unique, which is a critical feature that differentiates them from other collection types, like lists. They are also unordered collections, meaning the order in which items are added does not affect how they are stored or accessed, as their primary purpose is to facilitate quick lookups based on keys rather than maintain a specific order. Lastly, dictionaries in Python are mutable, allowing for changes, such as adding or removing key-value pairs after the dictionary has been created.