This is a business law question PLEASE I really need HELP !!! PLEASE answer ALL questions!!!! THANK YOU.

Gura finds a piece of land that she is interested in purchasing. She asks Roberto, the landowner, to hold the land for her while she makes a decision. Roberto says that for $1,000, he will hold the land for her while she decides, and Gura agrees. This is an example of a(n) O option contract O quasi-contract open-ended offer O implied-in-fact offer illusory contract Which of the following is true regarding when an offeree may reject an offer? Regardless of how long an offeror states that an offer will be held open, once the offeree rejects it the offer is terminated. An offer must remain open for at least seven (7) calendar days before an offeree may reject it. An offer must remain open for at least three (3) business days before an offeree may reject it. An offer must remain open for at least thirty (30) calendar days before an offeree may reject it. If the offeror states that an offer will be held open for a certain time period, it is open for that time even if the offeree rejects the offer prior to the expiration of the specified period. If a(n) ----- contract exists, the seller must hold the offer open until it expires in accordance with the contract. O unilateral O implied-in-law O option O executed O bilateral