For 2021, Rahal's Auto Parts estimates bad debt expense at 1% of credit sales. The company reported accounts receivable and an allowance for uncollectible accounts of $86,500 and $2,100, respectively, at December 31, 2020. During 2021, Rahal's credit sales and collections were $404,000 and $408,000, respectively, and $2,340 in accounts receivable were written off. Rahal's 2021 bad debt expense is: