Stan and Silvia Waterson go on a vacation and leave their 17 year old daughter, Jessie, in charge of the house and her two younger siblings. While the elder Watersons are away, a severe storm knocks down power lines and the electricity is off for a week. Since all the food in the refrigerator and freezer spoiled, Jessie talks the owner of a small grocery store into letting her have groceries on credit. When the Waterson parents come back home, the store demands payment from them for the groceries. On what basis must the parents pay for the groceries