Which of the Following Is True of Oral Contract Payments

Which of the following is true of oral contract payments?

A) In the case of part payment, an oral contract may be enforced for goods, for which payment has not been made and accepted.
B) An oral contract can be enforced if the buyer has made full payment on the contract.
C) Under the law of commercial paper, a check, or draft is an unconditional payment when delivered.
D) A check or promissory note tendered as payment, but refused by the seller, constitutes as an oral contract payment.