What Was the Basis of the NATO Alliance

What was the basis of the NATO alliance?

A) Members agreed to regard an attack against one member state as an attack against the entire alliance.
B) Members agreed to resist the spread of communism throughout the world.
C) Members agreed to regard any act of aggression by the United States as an act of aggression against their own country.
D) Members agreed not to develop or deploy nuclear weapons.
E) Members agreed to support peace movements throughout the world.