Why is encapsulation important in object-oriented design?

Encapsulation is a fundamental concept in object-oriented design that focuses on restricting direct access to an object's data and methods. By hiding the internal state of an object and requiring all interaction to occur through well-defined interfaces, encapsulation promotes data integrity and security. This means that the internal representation of the object can be changed without affecting the code that uses the object, making the system more maintainable and adaptable to change.

Encapsulation also facilitates the principle of abstraction where users interact with the object at a high level without needing to understand the implementation details. This separation of concerns minimizes the risk of unintended interference from outside elements, ensuring that the data remains valid and consistent throughout the object's lifecycle.

The other choices touch on important concepts but do not capture the essence of encapsulation as effectively. While minimizing system complexity and ensuring uniform behavior across objects are valuable design goals, they are not the primary function or benefit provided by encapsulation. Similarly, relationships among objects are inherent to object-oriented design and are not negated by encapsulation.