All of these statements about labor unions are true
a) unions tried to represent all workers, no matter their race, gender, or ethnic backgrounds
b) unions usually represented workers in a single industry, such as railroad workers
c) unions worked in order to advance the common interests of their members

  A) Unions tried to represent all workers, no matter their race, gender, or ethnic backgrounds.

Explanation:

  Labor unions are organizations that represent workers in many industries. Their activity is centered on collective bargaining over wages, benefits, and working conditions for their memberships. They also represent their members if there is a dispute with management over violations of contract provision.

  Some of the biggest unions in the country engage in lobbying activities and electioneering at the state and federal level.

  They do not represent all workers, they represent their members no matter race, gender, or ethnic. They are divided to represent different industries in order to be more focus on work activity.

  I hope this answer helps you.

i believe 5 is correct answer

use wikipedia, i think they have this.