Answer:
A
Step-by-step explanation:
The Taft-Hartley Act provides for the following: 
 
It allows the president to appoint a board of inquiry to investigate union disputes when he believes a strike would endanger national health or safety, and obtain an 80-day injunction to stop the continuation of a strike. 
It declares all closed shops illegal. 
It permits union shops only after a majority of the employees vote for them. 
It forbids jurisdictional strikes and secondary boycotts. 
It ends the check-off system whereby the employer collects union dues. 
It forbids unions from contributing to political campaigns.