The treatment of unauthorised immigrants by many countries is often cruel and lacking in compassion. Even refijgees from wartom or famine-stricken regions can find themselves imprisoned on arrival or deported back to the place they have fled. It is a terrible decision to have to take, but if we make an exception to the law for one person, we ought to make the same exception for everyone. If some illegal entrants were allowed to stay, others would have to be treated equally, and no country - especially one that is already overpopulated ・ could physically accommodate the numbers that would then follow. The regulations have to be enforced rigidly, even if this means turning away people in great need. Which ofthe following best illustrates the principle underlying the argument above?