What Does It Mean for Someone to Have a Right

What does it mean for someone to have a right, according to Mill?

A) To say that someone has a right to something is just to say that society expects the person to be free to have or do that thing.
B) To say that someone has a right to something is to say that society ought to defend his or her possession of or ability to do that thing.
C) To say that someone has a right to something is a purely legal claim, with no basis in morality proper.
D) To say that someone has a right to something is just a way of expressing an especially strong feeling about it.