On April 2nd, Kelvin sold $40,000 of inventory items on credit with the terms 1/10, n/30. If gross method was used to record the sales (cash) discounts, Kelvin should record:

a. $40,000 of "accounts receivable" on April 2nd

b. $400 of "sales discount" when the entire account was collected on April 20

c. $400 of "sales discount forfeited" when the entire account was collected on April 20

d. $39,600 of "accounts receivable" on April 2