With Regard to the Promise of Irrevocability, the CISG Differs

With regard to the promise of irrevocability, the CISG differs from the UCC in that the CISG ________.

A) requires the promise of irrevocability to be signed by both parties
B) requires the promise of irrevocability to be limited by time
C) does not require for the promise of irrevocability to be in writing
D) makes it mandatory only for the offeree, and not for the offeror, to obey the promise of irrevocability