What Are the Three Main Reasons That Employers Offer Discretionary

What are the three main reasons that employers offer discretionary benefits? (The Economics of Employee Benefits: Why Do Employees Offer Benefits?)

A) Employers have a cost advantage,the benefits help in recruiting and retaining workers and the company gets tax incentives to offer them
B) It's required to by law,the company gets tax incentives to offer them,employers have a cost advantage
C) The company gets tax incentives to offer them,the benefits help in recruiting and retaining workers,it's required to by law
D) The benefits help in recruiting and retaining workers,employers have a cost advantage,it's required to by law