Module design is used to maximize cohesion and minimize coupling. Which of the following is the key to implement this rule?

Explanation

Encapsulation packages the data and the operations that act on that data inside one module and hides the internal representation behind a narrow interface. Keeping everything that belongs together inside the module raises cohesion, while restricting other modules to the published interface removes shared data and internal dependencies, which lowers coupling — so encapsulation delivers both halves of the rule at once. Inheritance actually increases coupling between a subclass and its superclass, polymorphism is about interchangeable behaviour at run time, and abstraction is the broader idea of ignoring detail rather than the mechanism that enforces the boundary. Hence encapsulation is the key.