The owner of Sugar Daddy's Cakes and Catering telephoned the manager of O'Malia's grocery on April 29 and said "We will sell you 8-inch round single-layer chocolate cakes for half price. This offer will remain open through May 6." Based on these facts, when can Sugar Daddy's revoke its offer?

Group of answer choices

At any time before O'Malia's accepts the offer

Not until May 7

Not until a reasonable time after April 29

Not for three months after April 29