12. The Taft-Hartley Act: a. contains provisions that allow the president to invoke a cooling-off period of bargaining before a strike that threatens to imperil the public health and safety can begin. b. provides employee protection within union organizations. c. gives employees the right to organize and choose representatives to bargain collectively with their employers. d. mandates employers with 100 or more workers to give workers 60 days' advance notice of plant shutdowns that would affect at least 50 workers and of layoffs that would last more than six months and affect one-third of the workers at the site