On September 1, Sapphire Company loaned $120,000, at 10% annual interest, to a customer. $12,000 of interest and and $120,000 principal will be collected when the loan matures one year from the issue date. $4,000 of interest had been earned by December 31. Assuming adjustments are only made at year-end, what is the adjusting entry for accruing interest that Sapphire would need to make on December 31, the calendar year-end?