If accounts receivable are material, GAAP requires that the expense resulting from the failure of credit customers to pay their bills should A. be recognized in the period in which the account receivable proves to be uncollectible because that is the only date when the exact loss will be known B. be estimated and recorded in the period in which sales are made so that expenses are matched with revenues be estimated in the period in which sales are made and recorded into the balance sheet, but not recorded on the income statement until the customer actually defaults