During 2019, a company made credit sales for $420,000 and had returns and bonuses on sales for 40,000. In addition, the balances of accounts receivable and allowances for uncollectible accounts as of December 31, 2019 were $160,000 and 2,000, respectively. If the company makes provisions for doubtful accounts based on 5% of accounts receivable, then the amount of the adjustment for bad debt expense on December 31 will be:

a) $10,000 b) $19,000 c) $6,000 d) $8,000