Sprague Company uses the aging method to adjust the allowance for uncollectible accounts at the end of the period. At December 31, 2018, the balance of accounts receivable is $250,000 and the allowance for uncollectible accounts has a credit balance of $4,000 (before adjustment). An analysis of accounts receivable produced the following age groups:

Current ...................................... $150,000
60 days past due......................... 90,000
Over 60 days past due................ 10,000
                                                      $250,000

Based on past experience, Sprague estimates that the percentage of accounts that will prove to be uncollectible within the three age groups is 2% of the current balance, 8% of the 60 days past due balance, and 18% of the over 60 days past due balance. Based on these facts, the adjusting entry for uncollectible accounts should be made in the amount of

a. $8,000.

b. $12,000.

c. $17,000.

d. $16,000.