According to the Scrum Guide1, ordering Product Backlog items is solely up to the Product Owner's discretion. The Product Owner orders items in the Product Backlog to best achieve goals and missions. To do this, they optimize value by considering various factors such as cost and benefit, risk, dependencies, date needed, etc. The Product Owner is responsible for maximizing the value of the work the Development Team does. The Scrum Master is accountable for establishing Scrum as defined in the Scrum Guide. They do this by helping everyone understand Scrum theory and practice, both within the Scrum Team and the organization. Therefore, an appropriate action for the Scrum Master to take if the Product Owner is struggling with ordering the Product Backlog is to offer the Product Owner help in understanding that the goal of ordering the Product Backlog is to maximize value.