问题如下：
1. The retirement benefits paid during the year were closest to:
选项：
A. 280.
B. 3,000.
C. 4,000.
解释：
C is correct.
The retirement benefits paid during the year were closest to 4,000. The beginning obligation plus current and past service costs plus interest expense plus increase in obligation due to actuarial loss less ending obligation equals benefits paid (= 42,000 + 200 + 120 + (42,000 × 0.07) + 460 – 41,720 = 4,000). Beginning plan assets plus contributions plus actual return on plan assets less ending plan assets equals benefits paid (= 39,000 + 1,000 + 2,700 – 38,700 = 4,000).
考点：DB plan 的计算公式
解析：
从资产或从负债出发都可计算benefit paid:
从资产出发：根据公式:(注意plan asset中包含的是资产的真实收益而不是预期收益）
Plan assets at end of year =Plan assets at beginning of year + Employer contributions+ Actual return on plan assets - benefit paid
所以Benefit paid= 39,000 + 1,000 + 2,700 – 38,700 = 4,000
从负债出发：
PBO at end of year=PBO at beginning of year+CSC+PSC+int cost+A/L-benefit paid
其中，int cost=PBO beg *discount rate=42,000 × 0.07
所以benefit paid= 42,000 + 200 + 120 + (42,000 × 0.07) + 460 – 41,720 = 4,000
这题怎么知道用IFRS还是US GAAP呢
