On December 31, 2021, Staymore Inns' accumulated postretirement benefit obligation was $273 million. Retiree benefits of $27 million were paid at the end of 2021. Service cost for 2021 is $63 million Estimates and assumptions regarding future health care costs were revised in 2021, causing the actuary to revise downward the estimate of the APBO by $6 million. The actuary's discount rate is 8 %. There were no other significant accounts related to the plan at the end of 2021. What was the accumulated postretirement benefit obligation at January 1, 2021? Multiple Choice $200 million $210 million $225 million $273 million