What does the `override` keyword indicate in Kotlin?

The override keyword in Kotlin signals that a function in a subclass is providing a new implementation for a function that is defined in its parent class. This mechanism is crucial in object-oriented programming because it allows subclasses to modify or extend the behavior of inherited methods. By using the override keyword, Kotlin enforces a clear and explicit contract that the function being defined is intended to replace an existing function from the superclass, ensuring that the programmer’s intention is clear and preventing accidental overrides of methods that were not designed to be overridden.

This keyword also helps in maintaining the integrity of the inheritance structure by signaling to the compiler that a subclass intends to override a method from its parent class. If the specified method does not exist in the superclass, or if the method signature does not match, the compiler will throw an error, thereby aiding in avoiding runtime errors.

In terms of the other choices, defining a function does not require the override keyword; it is used when the intention is to replace an existing implementation. Assigning a default value to a variable does not involve override. Lastly, the final clause in Kotlin is used for classes and methods to prevent them from being subclassed or overridden, respectively, rather than indicating an override situation. Hence,