Regarding the Worker Adjustment and Retraining Notification (WARN) Act, the following statement is true: O Employers must give notice of plant closings and mass layoffs to all employees, including part-time workers. O Employers must give notice to employees that they will be subjected to polygraph tests. O Employers must give notice to employees that they are being subpoenaed by a court of law. O Employers must give prior notice to an "at-will" employee that he or she is being fired. O Employers must give notice to employees that a drug test will be conducted for all employees