Andy and April drive a car they borrowed from April's dad from their home in Indiana to the Grand Canyon in Arizona.While in Arizona, they were rear ended by a snowbird from Ohio named Gerry.The accident totaled the car, which was valued at $ 20,000 and caused about $10,000 in medical costs and damages between April and Andy's injuries.

Consider the additional facts for purposes of this question only.If April and Andy offer to settle the case with Gerry and Gerry accepts the offer, how is this settlement enforceable?