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$.$ public and protected both can be used.

b$.$ Only the public can be used.

c$.$ Only the protected can be used.

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