Which labor arrangement prohibits hiring workers who are not already union members and is generally illegal in the United States?

• A. Open shop
• B. Union shop
• C. Agency shop
• D. Closed shop

Answer: (D)

This question tests how union-security arrangements affect who can be hired. A closed shop means you can hire only people who are already union members, so non-members cannot be brought into the job. In the United States, that type of requirement has been prohibited at the federal level since the Taft-Hartley Act of 1947, and many states further limit such arrangements with right-to-work laws. So the practice effectively bars hiring non-union workers, which is why it’s generally illegal.

The other forms don’t impose a pre-employment union membership condition. An open shop hires without regard to union status; a union shop allows hiring non-members but requires joining the union after a set period; an agency shop requires paying union dues without requiring membership. These options don’t demand that only union members be hired, so they’re not illegal in the same way.