Patrick usually provides child care for six children. Parents leave their children at Patrick' s house in the morning and pick them up after work. At the end of each workweek, the parents pay Patrick at an hourly rate for the child care provided that week. The weekly income Patrick receives is usually adequate but not always uniform, particularly in the winter, when children are likely to get sick and be unpredictably absent. Which of the following plans, if put into effect, has the best prospect of making Patrick's weekly income both uniform and adequate? ['Increase the hourly rate to a level that would provide adequate income even in a week when half of the children Patrick usually cares for are absent.', 'Hire a full-time helper and invest in facilities for providing child care to sick children.', "Increase the number of hours made available for child care each day, so that parents can leave their children in Patrick's care for a longer period each day at the current hourly rate.", 'Replace payment by actual hours of child care provided with a fixed weekly fee based upon the number of hours of child care that Patrick would typically be expected to provide.']