The Product Owner does not make sure the Developers select enough from the Product Backlog for a Sprint to satisfy the stakeholders. The Developers are the ones who determine how many Product Backlog items they select for a Sprint, based on their capacity and the Sprint Goal1. The Product Owner and the Developers collaborate on the scope of the Sprint during Sprint Planning, but the final decision is up to the Developers2.
The Product Owner is accountable for maximizing the value of the product and the work of the Developers, and for managing the Product Backlog[3][3]. The Product Owner does not have the authority to tell the Developers how much work they should do, as this would violate the principle of self-management4.
References:
1: The Scrum Guide, November 2020, p. 6
2: The Scrum Guide, November 2020, p. 10
[3][3]: The Scrum Guide, November 2020, p. 6
4: Understanding and Applying the Scrum Framework, Scrum.org, accessed on December 16, 2023

Explanation
Answer A. Teach them that it is their responsibility to work with the other teams to create an
integrated Increment that is inclusive of all five team's work.
Explanation: According to the Scrum Guide, the Scrum Team is responsible for all product-related activities, including coordination and integration with other teams. The Scrum Master should teach the Developers how to work with the other teams to create a potentially releasable product increment that meets the Definition of Done and the Product Goal. One way to facilitate this coordination is to use a Scrum of Scrums meeting, which is a daily or periodic meeting where representatives from each team share their progress, plans, and impediments. The Scrum of Scrums meeting is not mandatory, but it can help the teams align their work and resolve dependencies.
The other options are not correct because they violate the principles of Scrum, such as self-management, empiricism, and transparency:
* B. Collecting the Sprint tasks from the teams and merging them into a consolidated plan for the entire Sprint is a centralized and controlled way of coordination that undermines the self-management and autonomy of the teams. The Scrum Master should not act as a project manager or a coordinator, but as a servant-leader and a coach who enables the teams to manage their own work.
* C. Visiting the five teams each day to inspect that their Sprint Backlogs are aligned is a micromanagement and inspection approach that does not respect the trust and transparency of the teams.
The Scrum Master should not interfere with the work of the teams, but support them in creating a shared understanding of the product vision, goals, and requirements.
* D. Teaching the Product Owner to work with the lead developers on ordering Product Backlog in a way to avoid too much overlap during a Sprint is a suboptimal and inefficient way of coordination that does not leverage the collective intelligence and creativity of the teams. The Product Owner should not rely on a few individuals to order the Product Backlog, but collaborate with all the teams and stakeholders to maximize value delivery.
References:
* [Scrum Guide], section 2.2: "The Scrum Team is responsible for all product-related activities from stakeholder collaboration, verification, maintenance, operation, experimentation, research and development, and anything else that might be required."
* Scrum Of Scrums - Guide to Agile Scaling Frameworks - Agilest®: "The coordination of the various teams is done in a Scrum of Scrums meeting which can be held daily, twice a week, or at a minimum, once a week. Each Scrum team has its ScrumMaster or a designated team member attend the Scrum of Scrum meeting as its representative."