Plum Painting Services has a weekly payroll of $21,000. December 31 falls on Wednesday and Plum will pay its employees the following Monday (January 5) for the previous full week. Assume that Plum has a five-day workweek and has an unadjusted balance in Salaries Expense of $820,000 at December 31. What amount should be debited to Salaries Expense on December 31? O $8400 O $21,000 O $12,600 O $820,000