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. $100,000
b. $112,000.
c. $90,000.
d. $107,200.