9) At the end of its 2020 fiscal period, Barton's Books, a sole proprietorship, has ending accounts receivable of $87,500. of this amount, it is estimated that $3,400 are doubtful of collection. A reserve for income tax purposes is claimed for this amount. During 2021, $3,600 of accounts receivable are written off as bad debts At the end of its 2021 fiscal period, accounts receivable total $103,200, with $4,100 of this amount considered doubtful of collection. What are the income tax consequences with respect to the accounts receivables fof the 2021 fiscal period