Consider the following class definitions.

publ ic class ClassA

$\{$

publ ic St r ing getValue$()$

$\{$

return $"$A$"$;

$\}$

publ ic void showValue$()$

$\{$

System.out $.$pr int $($getValue$())$ ;

$\}$

$\}$

publ ic class ClassB extends ClassA

$\{$

publ ic St r ing getValue$()$

$\{$

return $"$B$"$;

$\}$

$\}$

The following code segment appears in a class other than ClassA or ClassB.

ClassA obj $=$ new ClassB$()$ ;

obj $.$showValue$()$ ;

What, if anything, is printed when the code segment is executed?

$($A$)$ A

$($B$)$ B

$($C$)$ AB

$($D$)$ BA

$($E$)$ Nothing is printed because the code does not compile