An aging of a company's accounts receivable indicates that $4,000 are estimated to be uncollectible. If Allowance for Doubtful Accounts has a $900 credit balance, the adjustment to record bad debts for the period will require a debit to Bad Debts Expense for $4,000 debit to Allowance for Doubtful Accounts for $3,100 debit to Bad Debts Expense for $3,100. credit to Allowance for Doubtful Accounts for $4,000