The trolley management method refers to an innovative management model that integrates service objects into the service system and taps the potential resources of the service objects to improve the management service level with the service provider. This mode is for service providers and service recipients. It is a win-win strategy. According to the definition above, Which of the following options are part of the trolley management method:. ['The student parent group arranged for the parents to take turns cleaning the class for free, and the school saved money for this.', " bookstore encourages customers who come to buy books and read books to bring small folding stools. Customers feel very intimate and the bookstore's sales performance has greatly improved.", 'ao Zhang quit his babysitter and started to do the housework himself.', 'In order to establish a corporate image of "environmental protection, energy saving, and responsibility", D supermarket issues electronic red envelopes to consumers who bring environmentally friendly packaging bags.']