Look at the following code and choose the right option for the word :

$//$Shape$.$ java

public class Shape $\{$

protected void display$()\{$

$\}$

System.out.println$("$Display$-$base"$)$;

$\}$

$//$ Circle. java

public class Circle extends Shape $\{<$

$<$ access modifier void display$()\{$

$\}$

System.out.println$("$Display$-$derived"$)$;

$\}$

a$.$ Only the public can be used.

b$.$ Only the protected can be used.

c$.$ public, protected, and private can be used.

d$.$ public and protected both can be used.