What does encapsulation generally refer to in object-oriented programming?

Encapsulation in object-oriented programming primarily refers to the practice of restricting access to the internal state of an object and exposing only what is necessary through public methods, commonly known as getter and setter methods. This concept ensures that the internal representation of an object is hidden from the outside, which helps prevent unintended interference and misuse of the object's data.

By encapsulating the data, developers can protect the integrity of the object, allowing changes to the internal state without affecting external code that relies on the object. This encapsulation promotes modular design, making it easier to maintain and modify code without introducing bugs in other parts of the program. It also facilitates a clear interface for interacting with objects, improving code readability and usability.

The other choices do not accurately capture the essence of encapsulation. Sharing variables among different classes pertains more to collaboration between classes rather than protective data management. Creating multiple instances of a class relates to object instantiation, and reducing the size of code does not necessarily connect to encapsulation's primary purpose of managing and securing an object's state.