A payment system allows different types of payment methods $($credit card, PayPal, etc.$).$ The PaymentProcessor class handles all the payment logic. Each time a new payment method is introduced, the class must be modified to add a new payment type.

Which principle is being violated here, and how can you refactor the code?

Open$-$Closed Principle $($OCP$)$; by creating a new payment method class for each payment type and using an interface or abstract class for the payment processor.

Single Responsibility Principle $($SRP$)$; by separating payment methods into different classes.

Liskov Substitution Principle $($LSP$)$; by ensuring that each payment method can substitute another without changing the program behavior.

Dependency Inversion Principle $($DIP$)$; by depending on high$-$level abstractions instead of low$-$level modules.