Which of the Following Is a Basic Obligation or Right

Which of the following is a basic obligation or right of the buyer and seller concerning the payment for goods?

A) The price of the goods must be paid in cash.
B) If there is no agreement for extending credit to the buyer, the buyer must pay for the goods on delivery.
C) If all or part of the price of goods is payable in real property, then both the transfer of goods and real property are covered by the law of sales of goods.
D) The buyer has the right to inspect the goods before payment under all circumstances.