Which of the Following Statements Is True

Which of the following statements is true?

A) Craft unions restrict membership to workers with specific skills.
B) There are two basic types of unions: local and national.
C) Members of craft unions typically work for just one company over the course of a year.
D) Craft unions don't have a lot of power over the supply of skilled workers because those people can get jobs anywhere.
E) Industrial unions include mostly skilled workers.