Allowance for Doubtful Accounts has a credit balance of $1,390 at the end of the year (before adjustment), and an analysis of customers' accounts indicates uncollectible receivables of $20,504. Which of the following entries records the proper adjustment for bad debt expense? a. debit Bad Debt Expense, $19,114; credit Allowance for Doubtful Accounts, $19,114 b. debit Allowance for Doubtful Accounts, $21,894; credit Bad Debt Expense, $21,894 c. debit Allowance for Doubtful Accounts, $19,114; credit Bad Debt Expense, $19,114 d. debit Bad Debt Expense, $21,894; credit Allowance for Doubtful Accounts, $21,894