Sullivan signs an employment agreement with Keller Construction. Two days after signing, Sullivan receives a job offer from Big Sky Construction for considerably more money. He explains the situation and asks to be released from the Keller contract. Keller agrees orally, provided Sulivan will help them find a replacement. Is this release valid?

$($A$)$ No$,$ because the release agreement is not supported by consideration.

$($B$)$ No$,$ because a release agreement must be in writing to be valid.

$($C$)$ Yes, the release agreement meets the requirements for a valid release.

$($D$)$ We cannot say without knowing whether Sullivan has yet done any work for Keller.