Consider the following Java code:

public class Invoice $\{$

$$public void createInvoice$()\{$

$//$ logic to create invoice

$\}$

$$public void printInvoice$()\{$

$//$ logic to print invoice

$\}$

$$public void emailInvoice$()\{$

$//$ logic to email invoice

$\}$

$\}$

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

Single Responsibility Principle $($SRP$)$; split printInvoice$()$ and emailInvoice$()$ into separate classes.

Liskov Substitution Principle $($LSP$)$; ensure subclasses can extend the behavior of Invoice.

Open$-$Closed Principle $($OCP$)$; add new functionality to modify the behavior of createInvoice$().$

Interface Segregation Principle $($ISP$)$; divide the methods into multiple interfaces.