Abbott company uses the allowance method of accounting for uncollectible accounts. abbott estimates that 3% of net credit sales will be uncollectible. on january 1, 2010, the allowance for doubtful accounts had a credit balance of $2,400. during 2010, abbott wrote-off accounts receivable totaling $1,800 and made credit sales of $100,000. there were no sales returns or sales discounts during the year. after the adjusting entry, the december 31, 2010, balance in the bad debt expense would be a. $1,200b. $3,000c. $3,600d. $7,200