In 2016, Warehouse 13 had net credit sales of $850,000. On January 1, 2016, Allowance for Doubtful Accounts had a credit balance of $18,000. During 2016, $27,000 of uncollectible accounts receivable were written off. Past experience indicates that the allowance should be 10% of the balance in receivables (percentage of receivable basis). If the accounts receivable balance at December 31 was $160,000, what is the required adjustment to the Allowance for Doubtful Accounts at December 31, 2016? Select one: a. $16,000 b. $160,000 c. $27,000 d. $25,000