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

#include<iostream.h> 
class CuriousTab
{
    int x; 
    float y; 
    public:
    CuriousTab(int x)
    {
        x = x;
    }
    CuriousTab(int p = 0, int q = 10)
    {
        x = p += 2; 
        y = q * 1.0f;
    }
    void SetValue(int &y, float z)
    {
        x = y;
        y = (int)z;
    }
    void Display(void)
    {
        cout<< x;
    }
};
int main()
{
    int val = 12; 
    CuriousTab objCuriousTab(val); 
    CuriousTab objTmp();
    objCuriousTab.SetValue(val, 3.14f); 
    objCuriousTab.Display(); 
    return 0; 
}

#include<iostream.h> 
int main()
{
    int x = 10, y = 20;
    int *ptr = &x;
    int &ref = y;

    *ptr++;
     ref++;    

    cout<< x << " " << y;
    return 0; 
}

#include<iostream.h> 
class CuriousTabBase
{
    public:
    int x, y; 
    public:
    CuriousTabBase(int xx = 0, int yy = 0)
    {
        x = xx;
        y = yy; 
    } 
 };
class CuriousTabDerived : public CuriousTabBase
{
    private:
        CuriousTabBase objBase; 
    public:
    CuriousTabDerived(int xx, int yy) : CuriousTabBase(xx), objBase(yy)
    {
        cout << x          << " " 
             << this->x    << " "  
             << CuriousTabBase::x << " "     
             << this->objBase.x ;
    } 
    ~CuriousTabDerived()
    { }
};
int main()
{
    CuriousTabDerived objDev(11, 22); 
    return 0;
}

#include<iostream.h>
class CuriousTab
{
    int x, y, z; 
    public:
    CuriousTab(int x = 100, int y = 30, int z = 0)
    {
        this->x = x; 
        this->y = y;
        this->z = z; 
        Display();
    }
    void Display()
    {
        cout<< x << " " << y << " " << z;
    }
};
int main()
{
    int a = 0, b = 1, c = 2; 
    int &x = ++a; 
    int &y = --b; 
    int z = c + b - -c; 
    CuriousTab objCuriousTab(x, y, z); 
    return 0; 
}