A company using the perpetual inventory system purchased inventory worth $21,000 on account with terms of 2/10, 1/30. Defective inventory of $1,000 was returned two days later and the accounts were appropriately adjusted. If the invoice is paid 10 days after the invoice date, the amount of the purchase discount that would be available to the company is O A $400 OB $440 OC. $420 OD. $410