Which of the Following Statements Regarding Vesting in a Defined

Which of the following statements regarding vesting in a defined benefit plan is correct?

A) Under a cliff vesting schedule, a portion of an employee's benefits vest each year.
B) Under a graded vesting schedule, an employee's entire benefit vests all at the same time.
C) When an employee's benefits vest, she is entitled to participate in the employer's defined benefit plan.
D) When an employee's benefits vest, she is legally entitled to receive the vested benefits.