Which of the following criteria is NOT suitable for prioritizing requirements?

Effort for validation is not typically considered suitable for prioritizing requirements because prioritization focuses primarily on how each requirement affects the overall goals and success of a project or product. When establishing priorities, the goal is to concentrate on criteria that directly influence the value of the requirement to the stakeholders and the end-users.

The impact on the operational system, influence on business success, and costs from implementation are all critical factors that help determine how essential a requirement is to achieving the desired outcomes. They allow project teams to assess which requirements will deliver the most value, align with business strategies, and fit within budgetary constraints. Evaluating the effort for validation does not directly relate to the requirement’s contribution to the system's performance or business objectives, and therefore, it is not a suitable criterion for prioritization.