Read the scenario and answer the questions that follow.

Julie is selling her car. She places an advertisement online, together with several photographs of the car, as follows:

Toyota Camry 1999, green in colour, air conditioned, 185,000 kms, logbooks available. $4,000. Email j..e@

On Tuesday, Brian sends Julie the following email:

I would like to buy the car you've advertised - it's the same as one I used to have that I was very happy with. I can offer you $3,500 for it.

Later that day, Julie replies as follows:

Unfortunately, the lowest price I can sell the car for is $3,750. If you can arrange to pay me before next week, I will sell the car to you for that amount.

On Wednesday night, Julie's son Alex asks whether he can buy the car. Alex doesn't have enough money, but says if Julie will sell the car to him for $2,500 he will paint her house and he also promises to have dinner with his parents every Sunday night and to spend more time studying for his University course. Julie's house does need painting, and she has already got a quote for $1,500 for the work. Julie agrees to sell the car to Alex on this basis.

On Thursday, Julie checks her emails and finds an email from Brian that reads as follows:

I've been to the bank, and I can afford $3,750 after all, so I'd like to buy the car for that amount. I have the money with me - when can I bring it over and pay for the car?

Brian's message has been in Julie's email Inbox since Wednesday morning. With whom does Julie have a contract to sell the car, Brian or Alex?