The Product Owner is accountable for maximizing the value of the product resulting from the work of the Scrum Team. They are also accountable for effective Product Backlog management, which includes clearly expressing Product Backlog items, ordering them to best achieve goals and missions, ensuring that the Product Backlog is transparent, visible and understood. The Product Owner may do the above work or may delegate the responsibility to others. However, the Product Owner remains accountable1.
When working with multiple Scrum Teams on the same product, the Product Owner should ensure that there is a shared understanding of the Product Goal among all the teams and stakeholders. The Product Goal is the long-term objective for the Scrum Team. They must fulfill (or abandon) one objective before taking on the next2. The Product Owner should also collaborate with the Developers to create and refine Product Backlog items that are valuable, feasible, and testable. The Developers are accountable for creating a plan for the Sprint, the Sprint Backlog1. The Product Owner should trust the Developers to self-organize and deliver the most valuable increments possible.
The other options are not recommended strategies for the Product Owner, as they may introduce unnecessary complexity, confusion, and waste. Adding component team Product Owners, enlisting the Program Management Office, or assigning sub-Product Owners may create silos, dependencies, and conflicts among the teams and stakeholders. These roles may also undermine the authority and accountability of the Product Owner, and reduce the transparency and alignment of the Product Backlog. The Product Owner should work with the Scrum Master and the Developers to find ways to optimize the value delivery and collaboration across the teams, rather than creating intermediaries or proxies34. References: 1: Scrum Guide 2: Understanding and Applying the Scrum Framework 3: Managing Products with Agility 4: Evolving the Agile Organization

According to the PSPO II resources, a product owner should optimize the value of the product and the work of the Scrum Team1. One way to do this is to improve the value experienced by the customer, which is the perception and evaluation of the product by the customer2. A price increase can be justified if the customer perceives that the product delivers more value than the cost3. This can be achieved by enhancing the product quality, functionality, usability, or design, or by providing additional benefits or services to the customer4. The other options are not effective ways to justify a price increase, as they may either reduce the value experienced by the customer, or increase the cost without increasing the value. References:
1: The Scrum Guide
2: User Experience
3: Value-Based Pricing
4: 8 Techniques to Justify a Price Increase
5: Justification for a Price Increase: Positioning For Success