Need help,, I do not understand why

Allowance for Doubtful Accounts has an unadjusted balance of negative $1,100 at the end of the year, and an analysis of customers' accounts indicates doubtful accounts of $12,900. Which of the following records the proper provision for doubtful accounts? Select one: a. Decrease Allowance for Doubtful Accounts, $14,000; decrease Bad Debts Expense, $14,000 b. Increase Bad Debts Expense, $14,000; increase Allowance for Doubtful Accounts, $14,000 c. Decrease Allowance for Doubtful Accounts, $11,800; decrease Bad Debts Expense, $11,800 d. Increase Bad Debts Expense, $11,800; increase Allowance for Doubtful Accounts, $11,800