A year-end review of Accounts Receivable and estimated uncollectible percentages revealed the following: Days Outstanding 1-30 days 31-60 days 61-90 days Over 90 days Accounts Est. Percent Receivable Uncollectible $64,000 2% $43,000 4% $25,000 10% $7,000 52% Before the year-end adjustment, the credit balance in Allowance for Uncollectible Accounts was $1,400. Under the aging-of-receivables method, the Uncollectible Account Expense at year-end is: OA. $7,740. OB. $1,280. OC. $9,140. OD. $10,540.