What will be the output of the following C code (run without

What will be the output of the following C code (run without any command line arguments)?

 #include <stdio.h>
    int main(int argc, char *argv[])
    {
        while (argc--)
        printf("%s\n", argv[argc]);
        return 0;
    }

1. Compilation Error
2. Segmentation fault
3. Undefined behaviour
4. Nothing
5. main

main