According to a study by Mercer, many supplemental executive retirement plans (SERP) are unfunded. Why do companies choose to create SERPs that are not funded? 

a. SERPs are used to attract high salaried employees, and the company contributions are just too expensive. 

b. Employers do not receive a tax deduction for the contributions to the plan until the employee actually receives the benefits. 

c. SERPs have to be defined benefit plans, and companies do not want to be locked into funding a defined benefit plan. 

d. Employers are required to offer a SERP to all employees if they are planning to make contributions to fund the SERP