Which of the following is NOT a feature of object-oriented programming?

Object-oriented programming (OOP) is characterized by several core features, including encapsulation, inheritance, and polymorphism. These foundational concepts provide a framework for structuring software in a way that promotes reusability, scalability, and ease of maintenance.

Encapsulation refers to the bundling of data and methods that operate on that data within a single unit, or object, while restricting direct access to some of the object's components. This concept enhances data integrity and protects the internal state of an object.

Inheritance allows a new class to inherit properties and behaviors (methods) from an existing class, facilitating code reuse and establishing a hierarchical relationship between classes. This supports the creation of more complex systems while leveraging existing functionality.

Polymorphism enables one interface to be used for a general class of actions. The specific action is determined at runtime, allowing for flexibility in how code executes and interacts with different object types.

Threading, on the other hand, is not a fundamental feature of object-oriented programming. While it is a technique used in concurrent programming to allow multiple sequences of operations to execute simultaneously, it does not directly relate to the principles of OOP. Therefore, the correct choice for what is NOT an OOP feature is threading.