What will be the output of the following C++ code?

#include <iostream>
using namespace std;
void duplicate (int& a, int& b, int& c)
{
    a *= 2;
    b *= 2;
    c *= 2;
}
int main ()
{
    int x = 1, y = 3, z = 7;
    duplicate (x, y, z);
    cout << x << y << z;
    return 0;
}

A. A collection of functions B. A reserved keyword in C++ C. A blueprint for creating objects D. A way to declare arrays of data

A. new B. create C. object D. None of the above

A. A reserved keyword in C++ B. An instance of a class C. A way to declare arrays of data D. None of the above

A. To hide the implementation details of a class B. To create multiple instances of a class C. To initialize the object's data members D. To destroy the object