For 2018, 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, 2017. During 2018, Rahal's credit sales and collections were $404,000 and $408,000, respectively, and $2,340 in accounts receivable were written off. Rahal's 2018 bad debt expense is:

a) $2,100.

b) $2,340.

c) $4,080.

d)None of these answer choices are correct.