The correct implementation of the CheckPaymentProcessor class must adhere to the PaymentProcessor interface. To accomplish this:
* Use the implements keyword to signify that the CheckPaymentProcessor class is implementing the PaymentProcessor interface.
* Define the pay method in the CheckPaymentProcessor class, as it is required by the PaymentProcessor interface.
* The pay method must match the method signature defined in the PaymentProcessor interface (void pay (Decimal amount)).
Explanation of Option D:
* It uses implements PaymentProcessor to correctly indicate that the class adheres to the interface.
* The pay method is properly implemented with the required method signature and includes a placeholder for functional code.
Other Options:
* Option A: The pay method is not implemented correctly (no method body).
* Option B: Incorrect use of extends instead of implements (interfaces are implemented, not extended).
* Option C: Same issue as Option B, with a slight variation in formatting.