Hierarchy

 #include <iostream>

using namespace std;

class A {
    public:
        void Method_A() {
        cout << "Method_A" << endl;
    }
};



class B:public A {
    public:
        void Method_B() {
        cout << "Method_B" << endl;
    }
};



class C:public A {
    public:
        void Method_C() {
        cout << "Method_C" << endl;
    }
};


class D:B,C {
    public:
        void Method_D() {
        cout << "Method_D" << endl;
    }

    void Display() {
        B::Method_A();
        Method_B();
        Method_C();
        Method_D();

    }
};



int main() {
    D obj;
    obj.Display();
    return 0;
}