Which principle of OOP is primarily concerned with data protection?

Encapsulation is a fundamental principle of object-oriented programming (OOP) that focuses on restricting access to certain components of an object and bundling the data (attributes) and methods (functions) that operate on the data within a single unit or class. This principle helps in data protection by controlling how the data within an object is accessed and modified.

By exposing only a limited interface to the outside world and keeping certain data points private, encapsulation helps prevent unintended interference and misuse of an object's internal state. This means that any modification to the data can only be performed through well-defined methods, often called getters and setters, which can enforce rules on how that data can be accessed or modified, thus adding a layer of security and integrity to the data.

In contrast, the other principles serve different purposes: polymorphism allows for methods to operate differently based on the object invoking them, abstraction simplifies complex systems by modeling classes based on essential characteristics, and inheritance facilitates the creation of new classes based on existing ones, promoting code reuse. However, none of these principles primarily address the concern of safeguarding data as encapsulation does.