On 1 August, a Makes a Telephone Call to B

On 1 August, A makes a telephone call to B, stating that she would like to sell her car to B for £13,000. B asks for some time to consider this offer. However, on 8 August, B hears from A's mother that A already sold the car to a third party. B immediately hires a courier to deliver a letter to A, asking A whether she can deliver the car by Friday. On the same day, A writes to B saying that she is withdrawing the offer, and B sees this letter on 9 August.
Which statement is correct?

A) There is no contract, as B could not have accepted the offer.
B) There is no contract, as B's reply constitutes a counter-offer, which A did not accept.
C) Acceptance was complete, and thus the contract was made, as of 8 August.
D) There is no contract, as A effectively revoked the offer on 8 August.