Defined benefit plans have three measures of the plan liability -- Vested benefit obligation (VBO), Accumulated benefit obligation (ABO), and Projectedbenefit obligation (PBO).

A. Which of the three is the "best" (in your view) measure of a pension plan's liability at the end of a fiscal year (say 12/31/2017)?Briefly explain your answer, why do you believe that to be true?

B.BizarreCo. discloses the amount of its ABO, VBO and PBO as of 12/31/2017.They are all the same, $21,500,000!It's not a typo or a mistake.What circumstances must exist to explain that situation?