Which of the Following Statements Is False

Which of the following statements is false?

A) Long-term supply contracts cannot be entered into anonymously; the buyer and seller know each other's identity. This lack of anonymity may have strategic disadvantages.
B) A futures contract is an agreement to trade an asset on some future date, at a price that is locked in today.
C) An alternative to vertical integration or storage is a long-term supply contract.
D) Long-term supply contracts are unilateral contracts determined by a seller.