Concept:Discounts reduce the amount payable, but the discount offered for early payment is known as a cash discount.Explanation:A cash discount is given by the seller to encourage the buyer to pay the invoice promptly, usually within a specified period.It depends on the timing of payment, not on the quantity purchased or the season of sale.Other discounts like trade, quantity, and seasonal discounts are based on different factors such as bulk buying, distribution margins, or seasonal demand.Answer:A. cash discount