6.13.33.Which of the following constructor signatures must exist in the Demo class for DerivedDemo to compile correctly?
class Demo{
}
public class DerivedDemo extends Demo{ int M, N, L ; public DerivedDemo( int x, int y ){
M = x ; N = y ;
} public DerivedDemo( int x ){ super( x );
}
}
A. public Demo(int a, int b).
B. public Demo(int c).
C. public Demo().
D. There is no requirement for a constructor in Demo.