What was the main reason that the united states adopted policies to stop the spread of communism around the world ?

In a group discussion, which of these is the best example of synthesis claims into a single conclusion?

Those who resisted the mongol invaders were attacked and their towns burned; those who cooperated with them also were attacked and had their towns burned. were treated fairly. were taken into the tribes and treated as mongols. were sent away to find new homes.

Public opinion is difficult to define