Which of the following describes an option contract? Select all that apply.

A contract in which the offeror forfeits his right to revoke the offer in exchange for valid consideration (usually money) from the offeree.

A contract that is revocable.

A contract in which one or both parties may choose among a specified number of terms e.g., whether to purchase 10 units of widgets at $100 per unit or 25 units of widgets at $85 per unit.

A contract in which either party has the option to back out.