* Transparency is one of the three pillars of Scrum, along with inspection and adaptation. Transparency means that all aspects of the Scrum process and the product are visible and understandable to everyone who needs to work on or with them. Transparency enables effective inspection and adaptation, which are essential for delivering valuable products and improving the Scrum Team's performance.
* All Scrum artifacts must be transparent to ensure sufficient accuracy of inspection. Scrum artifacts
* include the Product Backlog, the Sprint Backlog, and the Increment. The Product Backlog is an ordered list of everything that is known to be needed in the product. It is the single source of truth for the Scrum Team and the stakeholders. It contains all the requirements, features, functions, enhancements, fixes, and anything else that can deliver value to the customers and users of the product.
* Two measures that ensure that the Product Backlog is transparent are:
* The Product Backlog is ordered: The Product Owner orders the items in the Product Backlog based on factors such as value, risk, priority, dependency, feedback, or market conditions. The order of the Product Backlog items provides a clear and consistent indication of what is most important and urgent for the product. The order of the Product Backlog items also helps the Scrum Team and the stakeholders to plan and forecast effectively.
* The Product Backlog is available to all stakeholders: The Product Owner makes the Product Backlog visible and accessible to everyone who has a stake in the product, such as customers, users, sponsors, managers, or other teams. The availability of the Product Backlog enables transparency, collaboration, feedback, and alignment among all parties involved in the product development.
* The other options are not valid or relevant measures to ensure that the Product Backlog is transparent.
They are either too restrictive, arbitrary, or unrelated to the Product Backlog's transparency. They are:
* Each Product Backlog item has a MoSCoW priority: MoSCoW is a technique for prioritizing requirements based on their importance: Must have, Should have, Could have, or Won't have.
While this technique can be useful for some products or contexts, it is not a mandatory or universal way to order the Product Backlog items. The Product Owner may use other factors or methods to order the Product Backlog items based on their value and relevance for the product.
* The Product Backlog only has work for the next 2 Sprints: This is a too limiting and unrealistic measure for the Product Backlog. The Product Backlog should contain all the work that is known to be needed in the product, not just for the next 2 Sprints. The Product Backlog is a living artifact that evolves as the product and the market change. The Product Owner should continuously refine and update the Product Backlog to reflect the current and future needs and expectations of the customers and users.
* The Product Backlog is managed using a web-based tool: This is an irrelevant measure for the Product Backlog's transparency. The Product Owner can use any tool or format to manage the Product Backlog, as long as it is clear, concise, and valuable. The tool or format does not affect the transparency of the Product Backlog itself. What matters more is how the Product Owner communicates and collaborates with the Scrum Team and the stakeholders using the Product Backlog.
References:
* Scrum Guide: https://www.scrumguides.org/scrum-guide.html
* Transparency: https://www.scrum.org/resources/blog/transparency-scrum-value
* Product Backlog: https://www.scrum.org/resources/what-is-a-product-backlog
* MoSCoW: https://www.agilealliance.org/glossary/moscow/

In Scrum, non-functional requirements are part of the quality and completeness criteria for the product. They should be incorporated into the Definition of Done, ensuring that each Increment meets these requirements, making it potentially shippable and usable by stakeholders.

The Developers are the people in the Scrum Team who are committed to creating any aspect of a usable Increment each Sprint. The Developers are accountable for organizing and managing their work. Only the Developers can decide how to perform the work during the Sprint1. The Developers plan the work necessary to create an Increment that meets the Definition of Done during the Sprint Planning event. This is often done by decomposing Product Backlog items into smaller work items of one day or less. How this is done is at the sole discretion of the Developers. The Sprint Backlog is the set of Product Backlog items selected for the Sprint, plus a plan for delivering the product Increment and realizing the Sprint Goal1. The Developers are responsible for creating and maintaining the Sprint Backlog1. The Developers are not accountable for selecting the Product Owner, reporting productivity, or any other activities that are not related to creating a Done Increment that meets the Sprint Goal123. Reference:
Scrum Guide
What is a Developer?
Who Determines How Work Is Performed During The Sprint?
[What is Sprint Planning?]