The North Atlantic Treaty in the passage above most clearly supports which of the following concepts?

NATO is a treaty that reflects (B), collective defense—the idea that an attack on one member is an attack on all. Eliminate because NATO countries are typically capitalist, but a capitalist economy is not necessary for membership. Eliminate (C) because mutually assured destruction is what happens when two nuclear parties have large enough arsenals to eradicate each other—the document doesn't support this reading at all. Eliminate (D) because the "communist" alliance in the Cold War was the Warsaw Pact, not NATO.