Answer:
Date Account Title Debit Credit
December 31 Postretirement benefit expense $3,900
APBO $3,900
Explanation:
Service cost = Ending EPBO / Attribution period
= 63,600 / 20
= $3,180
Interest cost = Beginning EPBO * Years employed / Attribution period * Interest rate
= 60,000 * 4/20 * 6%
= $720
Postretirement benefit expense = 3,180 + 720
= $3,900
Credit to Accumulated Postretirement Benefit Obligation (APBO).