accounting question

63.In 2011, Garrison Company had net credit sales of $1, 125,000. On January 1, 2011, Allowance for Doubtful Accounts had a credit balance of $27,000. During 2011, $45,000 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 $300,000, what is the required adjustment to the Allowance for Doubtful Accounts at December 31, 2011? a. $30,000 b. $112,500 C. $48,000