ALVIN contract law mtq

Alvin runs a business selling expensive cars. Last Monday he mistakenly placed a notice on one car indicating that it was for sale for £5,000 when in fact its real price was £25,000. Bert later noticed the sign and, recognising what a bargain it was, immediately indicated to Alvin that he accepted the offer and would take the car for the indicated amount. Alvin, however, told Bert that there had been a mistake and that the true price of the car was £25,000, and he could buy it at that price. Bert insisted that he was entitled to get the car at the lower price, and when Alvin would not give it to him at that price Bert said that he would sue Alvin.
After Bert had left, Cat came in to the showroom and Alvin offered to sell her the same car for £25,000. Cat told Alvin that she would like to buy the car, subject to arranging finance, and she would be in touch soon to confirm.
On Tuesday Del came by and offered Alvin the full £25,000 asking price, which Alvin accepted.
They agreed Del would return on Friday to pay for the car and take it away

Question:
In relation to Alvin and Del, which TWO of the following statements are correct?

• A binding contract between Alvin and Del was created on Tuesday
• There is no binding contract until Del pays for the car
•There is no binding contract because Alvin’s acceptance was conditional on Del returning on Friday to pay for the car
• If Del does not return on Friday to pay for the car, he is in breach of contract

I know the answer is A and D, but there’s offer and acceptance for contract.
But my question is What is consideration by both parties? And intention to create legal relation is presumed Bcz it’s a commercial agreement?