The correct answer is - pull factors.
The increased freedom and much more employment opportunities in the United States can be considered as pull factors. They can be considered as pull factors because they are big reasons why people from all around the world got attracted to the idea of migrating to the United States, as they saw a nice chance to prosper and have a better life. Most of the countries were still struggling with the freedom issues, and the employment opportunities were either very limited, or badly payed, so no wonder that pople wanted to move in the United States.
The Berlin Blockade led the conflict between the USSR and
US/Western Allies as this blockade removed the railway access for the western
allies to gain access to the parts in Berlin which were under the control of
the allied forces.
It's probably D. To point out problems in the south given the subject of most of his marches was going against racism in the south
