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

#include <iostream>
using namespace std;
const int SIZE = 10;
class safe
{
    private:
    int arr[SIZE];
    public:
    safe()
    {
        register int i;
        for (i = 0; i < SIZE; i++)
        {
            arr[i] = i;
        }
    }
    int &operator[](int i)
    {
        if (i > SIZE)
        {
            cout << "Index out of bounds" <<endl;
            return arr[0];
        }
        return arr[i];
    }
};
int main()
{
    safe A;
    cout << A[5];
    cout  << A[12];
    return 0;
}

A. 5Index out of bounds
0

B. 40

C. 50

D. 51

Answer: Option A