An aging of a companies accounts receivable indicates that $9,000 are estimated to be uncollectible. If allowance for doubtful accouns has a $1,100 credit balance, the adjustment to record bad debts for the period will be : a. debit to bad debts expense for $900 b. debit to the allowance for doubtful accounts $7,900 c. debit to bad debts expense , $7,900 d. credit to allowance for doubtful accounts for $9,000