How to write a do while loop which ask user to try again if answer is incorrect?

Q: How to write a do while loop which ask user to try again if answer is incorrect?
Ans :
import java.io.*;
import java.util.Scanner;

class AskUser {
    public static void main(String[] args) {
         Scanner sc = new Scanner(System.in);
        String ans = "", play = "";
        Pattern p = new Pattern();   
       
        do {
            p.question();
            ans = sc.nextLine();
            if(ans != "a" || ans != "b" || ans != "c" || ans != "d") {
                if(ans.equals("c")) {
                    System.out.println("correct answer!");
                    break;
                } else {
                    System.out.println("incorrect! try again!");
                    System.out.print("Press y to continue : ");
                    play = sc.nextLine();
                }
            } else {
                System.out.print("Press y to continue : ");
                play = sc.nextLine();
            }
        } while (play.equals("y") || play.equals("Y"));
    }
   
    public void question() {
        System.out.println("What is the command key to exit a loop in java?");
        System.out.println("A : int");
        System.out.println("B : continue");
        System.out.println("C : break");
        System.out.println("D : exit");
        System.out.print("your answer : ");
    }
}