Final answer:
The Worker Adjustment & Retraining Notification (WARN) Act requires employers to give minimum 60 days' notice in case of plant closure or mass layoffs.
Step-by-step explanation:
The correct answer is a) Worker Adjustment & Retraining Notification (WARN) Act. The WARN Act requires employers with more than 100 employees to provide written notice 60 days before plant closings or large layoffs. This is to ensure that employees have adequate time to prepare and make necessary arrangements. For example, if a factory is going to shut down or if a company is planning to lay off a large number of employees, they must provide notice at least 60 days in advance.