The APBO increases each year by the: Multiple Choice Interest accrued on the EPBO and the portion of the EPBO attributed to that year. Interest accrued on the EPBO and the portion of the APBO attributed to that year. Interest accrued on the APBO and the portion of the APBO attributed to that year. Interest accrued on the APBO and the portion of the EPBO attributed to that year