When you take a multiple-choice test, you are relying on a means of retrieving information out of your long-term memory storage system that you .

in an effort to stem the tide of refugees attempting to leave east berlin, the communist government of east germany begins building the berlin wall to divide east and west berlin. construction of the wall caused a short-term crisis in u.s.-soviet bloc relations, and the wall itself came to symbolize the cold war.

i think it is the third one.