Answer:
The correct word for the blank space is: union shop.
Explanation:
A union shop also called an association shop, is a clause unions establish by which new employees must join a union after being hired. The term they have to do so varies from thirty (30) to ninety (90) days. Joining a union is mandatory so new hires can keep their jobs but it is not a requirement to be part of a union before being part of a company.