Answer
Hostility of business towards unions
Explanation
A Union is a society or association formed by people with a common interest or purpose. In the 19th Century the labor movement in the United States grew out of the need to protect the common interest of workers. For those in the industrial sector, organized labor unions fought for better wages, reasonable hours and safer working conditions. Later these Unions were unsuccessful in improving work conditions because of government intervention. The United States government usually supported the businesses instead of the workers/labor unions because they increased the national wealth. Hostility of business towards unions was also a factor that greatly limited them.
"The United States withdrew its support." was perhaps the most immediate result of Diem's refusal to hold elections, but it should be noted there were others as well.
"De facto" means "in fact, factually" - that something is, indeed, taking place. It is customarily used to denote a situation which is not dictated by law ("de jure") but which happens anyway - so the best answer is A. Law - this segregation is not required by law, but it takes place anyway, for example for financial reasons.
The unemployed was helped. The reason why is because when Roosevelt (who gave the new deal) became president, America was in the Depression.
