If there are multiple Scrum Teams working on the same product, all of the Scrum Teams must mutually define a Definition of Ready (DoR). The DoR is a checklist that the Product Owner must fulfill before a Product Backlog item can be presented at the Sprint Planning. This protects the Development Team from interruptions and disruptions during the Sprint.
It is false that all Scrum Teams must mutually define a Definition of Ready (DoR) that the Product Owner must fulfill before a Product Backlog item can be presented at the Sprint Planning. While having a DoR can be beneficial to ensure that Product Backlog items are well-prepared, it is not mandated by Scrum guidelines. The essential criteria for Product Backlog items is that they should be clear and detailed enough for the Development Team to work on them. Sprint Planning can proceed with items that may not be fully refined, and these can be further analyzed and developed during the Sprint.
B is correct