bool usernameEntered = true; bool passwordEntered = true; if (usernameEntered && passwordEntered) { // proceed with login } else { // prompt user to enter missing information }This code uses the And operator to check if both `usernameEntered` and `passwordEntered` are true, indicating that the user has entered both pieces of information required to log in. If both are true, the program proceeds with the login process. If either is false, the program prompts the user to enter the missing information. The Expr And statement is not part of a specific package library in C#. It is a built-in logical operator that can be used in any C# program.