Why Does the NATO Still Exist

Why does the NATO still exist?

A) NATO members want protection because the Soviet Union is still a possible threat.
B) NATO members still have common interests such as protection from terrorism.
C) Western European countries believe that NATO is the only reason the United States would help defend them if they were attacked.
D) The Warsaw Pact has increased its military spending and NATO has expanded in response.
E) Western European countries want NATO to protect them from a reunified and stronger Germany.