Amarillo Company experienced the following events during its first accounting period.

(1) Purchased $5,000 of inventory on account under terms 2/10/n30.

(2) Returned 1,000 of the inventory purchased in Event 1.

(3) Paid the remaining balance in account payable within the discount period for the inventory purchased in Event 1.

Amarillo uses the periodic inventory system and at the at the end of the accounting period only $1,000 of inventory remained. Amarillo started the accounting period with $1,000 in inventory. What was Cost of Goods sold for the period?

a. $2,920

b. $3,000

c. None of the Above

d. $3,920.