Advantages of defined benefit plans include all of the following, except

a. defined benefit plans are easy to design and easy to explain to employees

b. employees obtain a tax-deferred retirement savings medium

c. retirement benefits at adequate levels can be provided for all employees regardless of age

d. benefit levels are guaranteed both by the employer and, for some plans, by the PBGC

e. for an older highly compensated employee, a defined benefit plan will allow the maximum amount of tax-deferred retirement saving