Answer:
c. Elaine sends a letter by USPS next-day service to Travel Lines stating that she will buy the tickets.
Step-by-step explanation:
A contract is formed when the offerer communicates the terms of a sale or contract and the offeror accepts the terms
The contract is now enforceable.
In this case c. Elaine sends a letter by USPS next-day service to Travel Lines stating that she will buy the tickets.
By sending the notification of purchase on the next day, Elaine has created to contract.