Which of the following statement is correct about the program given below?

#include<iostream.h> 
int i, j; 
class CuriousTab
{
    public:
    CuriousTab(int x = 0, int y = 0)
    {
        i = x; 
        j = x; 
        Display();
    }
    void Display()
    {
        cout<< j <<" ";
    } 
}; 
int main()
{
    CuriousTab objCuriousTab(10, 20); 
    int &s = i; 
    int &z = j; 
    i++;
    cout<< s-- << " " << ++z; 
    return 0; 
}

#include<iostream.h>
long CuriousTabFunction(int x, int y = 5, float z = 5)
{
    return(++x * ++y + (int)++z);
}
int main()
{
    cout<< CuriousTabFunction(20, 10); 
    return 0;
}

#include<iostream.h> 
void MyFunction(int a, int b = 40)
{
    cout<< " a = "<< a << " b = " << b << endl;
}
int main()
{
    MyFunction(20, 30);
    return 0; 
}

#include<iostream.h>
long GetNumber(long int Number)
{
    return --Number;
}
float GetNumber(int Number)
{
    return ++Number;
}
int main()
{
    int x = 20;
    int y = 30;
    cout<< GetNumber(x) << " ";
    cout<< GetNumber(y) ;
    return 0; 
}

1. Pointer to a reference and reference to a pointer both are valid.
2. When we use reference, we are actually referring to a referent.