Why Does Public Figure Privilege Exist

Why does public figure privilege exist?

A) To discourage discussion about politicians so democracy can function in a more orderly fashion.
B) To encourage free discussion about public figures.
C) To prevent people from making a profit by slandering public figures.
D) To give special protections from defamation to public figures since they are in the public eye and their reputations matter more to them than the average person.
E) To allow people to make up stories about politicians and celebrities because these public figures are people of interest to the public.