Which statement best describe a major reason why western european countries joined nato after world war 2

The Soviet Union had shown that it wanted to expand its area of control in Eastern Europe this is the answer hope it helps

the consumer demand because the members have to be aware if people are going to buy what they want to sell in this case either energy drinks or a car wash.

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.