Please show numerical support for the following questions

Use the following information in answering questions 38 and 39 The Thirty something Advertising Agency provides the information below for the current calendar year the firm's books are closed Assume that annually on December 31. Credit sales (billings) $160,000 Accounts Receivable January 1 30,000 Accounts Receivable December 31 50,000 Cash collections from credit customers 135,000 Allowance for Uncollectible Accounts, January 1 6,200 cr Bad Debt Expense as a Percentage of Sales 5 The amount of bad debts written off during the year was: a. 1,800 b 5,000. c. 6, 200 d. 8,000 e $20,000