In the Cash Discount $500, 4/10 Net 30, the Number

In the cash discount $500, 4/10 net 30, the number $500 refers to

A) the original price owed on the merchandise.
B) the total amount owed if paid within 10 days.
C) the total discount in dollars, if the bill is paid on time.
D) the penalty in dollars if the bill is not paid within 10 days.
E) the total penalty in dollars if the bill is paid after 10 days.