21) The Allowance for Doubtful Accounts is necessary because A) uncollectible accounts that are written off must be accumulated in a separate account. B) management needs to accumulate all the credit losses over the years. C) when recording uncollectible accounts expense, it is not possible to know which specific accounts will not pay. D) a liability results when a credit sale is made. 22) The account Allowance for Doubtful Accounts is classified as a(n) A) contra account to Bad Debt Expense. C) contra account to Accounts Receivable. B) liability. D) expense. 23) The expense recognition principle relates to credit losses by stating that bad debt expense should be recorded A) in the same period as allowed for tax purposes. B) in the period of the loss. C) for an exact amount. D) in the period of the sale.