will someone show me how to get to the answer?

In 2017 the Golic Co. had net credit sales of $600,000. On January 1, 2017, the Allowance for Doubtful Accounts had a credit balance of $15,000. During 2017, $24,000 of uncollectible accounts receivable were written off. Past experience indicates that the allowance should be 10% of the balance in receivables (percentage-of-receivables 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, 2017? a. $16,000 b. $25,000 c. $31,000. d. $24,000