Which one of the following best describes the term "Merchant Discount Rate" sometimes seen in the news?

The incentive is given by a bank to a merchant for accepting payments through debit cards pertaining to that bank.

The amount paid back by banks to their customers when they use debit cards for financial transactions for purchasing goods or services.

The charge to a merchant by a bank for accepting payments from his customers through the bank's debit cards.

The incentive given by the Government, to merchants for promoting digital payments by their customers through Point of Sale PoS machines and debit cards.