Bitwise Operators - Programming

Q1:

What will be the output of the program?
#include<stdio.h>

int main()
{
    char c=48;
    int i, mask=01;
    for(i=1; i<=5; i++)
    {
        printf('%c', c|mask);
        mask = mask<<1;
    }
    return 0;
}

A 1

B 0

C -1

D 2

ANS:A - 1

No answer description is available. Let's discuss.