What serves as the single source of requirements for product changes in Scrum?

The Product Backlog serves as the single source of requirements for product changes in Scrum because it is a dynamic, ordered list that encompasses all desired work on the product. It includes features, bug fixes, technical improvements, and other elements essential for product development, which are prioritized by the Product Owner based on the value they bring to the stakeholders and the organization.

This backlog is continuously refined and updated to reflect changing priorities, new insights from stakeholders, and the evolving understanding of customer needs. The ongoing collaboration in the Scrum Team allows the Product Backlog to serve as a central point of reference that guides what needs to be done in upcoming Sprints and ensures that the work aligns with the overall vision for the product.

The other options, while important in their own contexts, do not fulfill the role of being the comprehensive source for all product requirements. The Sprint Backlog contains the selected items from the Product Backlog that the team commits to completing in a Sprint, but it doesn't encompass all requirements. The Definition of Done outlines the criteria that must be met for an increment to be considered complete, but it doesn't specify what needs to be built. The Release Plan provides an overview of how and when product increments will be delivered, but it does not serve as a repository