A Scrum Team requesting a hardening Sprint to integrate and test work produced in previous Sprints indicates several underlying issues. Firstly, the team's Definition of Done is likely not being adhered to during every Sprint, meaning that work is not consistently reaching a releasable state by the end of each Sprint. Secondly, the team's Definition of Done may be weak or incomplete, resulting in a build-up of technical debt that requires additional effort to address. Lastly, the Development Team may be struggling with their ability to regularly release during a Sprint, suggesting process or technical challenges. Each of these scenarios aligns with fundamental principles of Scrum, which emphasizes the importance of a well-defined Definition of Done and the ability to produce a potentially releasable Increment every Sprint. Therefore, the correct answers are that the team's Definition of Done is not adhered to, the Definition of Done is weak or incomplete, and the team is having difficulty with regular releases.