Michael, a recent college graduate, is on his way home for his new job. He gets caught in a snowstorm and is taken in by an elderly couple, who provide him with food and shelter. After the snowplows have cleared the road, Michael proceeds home. Michael's father, Thomas, is most appreciative of the elderly couple's action and in a letter promises to pay them $500 for the assistance they provided to Michael. The elderly couple, in need of funds, accepts Thomas's offers. Then, because of a dispute between Michael and Thomas, Thomas refuses to pay the elderly couple the $500. Discuss whether the couple can hold Thomas liable in contract for the services rendered to Michael.