In International Business Transactions,a Documentary Letter of Credit

In international business transactions,a documentary letter of credit:

A) is a method of payment for goods that reduces the seller's risk from the possibility that the goods will be shipped, but not paid for.
B) is a type of bill of lading.
C) is a guarantee by the seller's bank that it will pay the price of the exported goods if the seller breaches the contract.
D) All of the above.