Food Packagers Union Represents the Workers of Garden Variety,Inc

Food Packagers Union represents the workers of Garden Variety,Inc.The company does not require its new hires to join the union as a prerequisite to obtaining employment.Food Packagers would like Garden Variety to require the workers to join after a specified amount of time on the job.This would violate

A) federal labor law.
B) federal immigration law.
C) federal wage and hour laws.
D) no federal law.