Rebate on bills discounted is also called.

Explanation:

Bill discounted are those bills which are in cashed before the due date or before the date of maturity.

The person who writes the bill is known as the drawer and the person on whom the bill is written is known as drawee.

Earned discount is a discount that the drawer gives to the drawee, who pays before the discount date or on the discount date.

An expired discount is a discount that is not valid because its maturity period has come to an end.

The received discount is the discount that one receives at the time of clearing the bills.

Final Answer:

Hence, the correct answer is Option A: Unexpired discount.