Following are the account balances from the December 31 trial balance of Lark Company:

Accounts Receivable	$ 60,000
Allowance for Bad Debts	2,400	(dr)
Sales Revenue	405,000
Sales Returns and Allowances	15,000

If 10 percent of the Accounts Receivable is estimated to be uncollectible, the entry to record the estimate of bad debts would include a debit to Bad Debt Expense for:

a. $6,000

b. $3,600

c. $8,400

d. $6,240