Which of the Following Is an Option for an Employee

Which of the following is an option for an employee under the mandatory vesting established by ERISA:

A) to have 100 percent vesting after 10 years of employment
B) to have 25 percent vesting after five years, then 5 percent vesting a year for five years, then 10 percent vesting a year for five years, to achieve 100 percent vesting in 15 years
C) vesting under the rule of 45
D) all of the other specific choices are correct
E) none of the other specific choices are correct