A trial balance with selected accounts at their normal balances before adjustments included the following:

Sales: $850,000.

Sales returns and allowances : $28,000.

Accounts Receivable: $86,000.

Allowance for doubtful accounts: $1,520.

If the estimate of noncollectable is made by taking 2% of net sales, the amount of the adjustment is:

$13,400.

$17,000.

$16,440.

$19,480.