Roberto phones Alicia on Friday and offers to sell her his car for $5,000.00.Alicia tells him that she will get back to him.She emails Roberto the following (Thursday) offering $3,750.00 for the car. Roberto tells her that on Tuesday, he sold the car to Carlos for $4,500.00.Alicia is very angry and writes this email to Roberto "You didn't give me an expiry date for the offer, so it was still open when you sold the car to Carlos.What you did was illegal!!"

Applying the relevant and correct principle(s) of law discuss the following question:

i)Whether Alicia is correct?

2) Whether the sale to Carlos is valid and enforceable?