Which of the Following Statements Is True of Labor Unions

Which of the following statements is true of labor unions?

A) In the private sector, it is compulsory for workers to join unions.
B) It is much easier to form and maintain unions in the United States than in most other industrial nations.
C) Most business owners in the United States make enormous efforts to ensure that their own businesses are unionized.
D) Today, members of organized labor make up more than 30 percent of all wage and salary workers.
E) The political power of labor unions has waned over the last several decades.