Mars Inc Has a Defined Benefit Pension Plan

Mars Inc. has a defined benefit pension plan. On December 31 (the end of the fiscal year) , the company received the PBO report from the actuary. The following information was included in the report: ending PBO, $110,000; benefits paid to retirees, $10,000; interest cost, $7,200. The discount rate applied by the actuary was 8%. What was the beginning PBO?

A) $90,000.
B) $100,000.
C) $107,200.
D) $112,000.