He could add a 6th question, which is what does this return: int main(void) { return -1 == (~1 + 1) } I am fairly confident that the answer will be the sa

He could add a 6th question, which is what does this return: int main(void) { return -1 == (~1 + 1) } I am fairly confident that the answer will be the same on every system on which that is run, but technically, the C standard does not guarantee that it is the same unless you use C23.