On December 31, 2016, ABC Co. sells a merchandise on credit on terms of 2/15, n/30, and records the sale using the gross method. However, had the company used the net method, sales revenue reported at the time of sale would have been $3,500 less.The company is applying the balance sheet approach when recognizing uncollectibles, and estimates that 1.5% of receivables will be uncollectible. How much effect does this sale have on current period's allowance balance if the fiscal-year end is December 31?