which of the following are correct regarding a transition obligation resulting from 604585

Which of the following are correct regarding a transition obligation resulting from the adoption of a defined benefit postretirement plan?

1. I. A transition obligation may be recognized immediately.
2. II. The transition obligation represents the difference between the accumulated postretirement benefit obligation and the fair value of plan assets at the beginning of the year the plan is adopted.
3. III. A transition obligation may be amortized on a straight-line basis over a maximum period of twenty years.
   1. a. I and II.
   2. b. II only.
   3. c. I, II, and III.
   4. d. II and III.