Explain why the offer in the following facts has EITHER been revoked or has been accepted (It is only one or the other):

Bonnie offered to sell her laptop computer to Dale.The offer contained all of the necessary terms.The offer stated that it would remain open for 14 days and that Dale should send an acceptance by regular mail.On the 5^th day, Bonnie decided that she did not want to enter into the contract and sent a letter stating that the offer was terminated.Dale received and read the letter on the 8th day.However, Dale had sent an acceptance by regular mail on the 7^th day.