According to PRINCE2, an effective project board must have the ability to delegate appropriately. This characteristic is essential to ensure that decisions and tasks are assigned to the right members of the project management team, facilitating efficient governance and management of the project. References: PRINCE2
7 Foundation Handbook and official training materials.

As part of the recommended risk management procedure in PRINCE2, it is essential to regularly review risk management practices to ensure their effectiveness. This involves evaluating how risks are identified, assessed, and controlled throughout the project lifecycle. References: PRINCE2 Foundation Handbook, Risk Management section.

The project manager should record the impact assessment for a specific business opportunity in an 'Issue Report'. This management product is used to detail particular issues that might affect the project, including opportunities (which are treated like positive risks), and provides a basis for decision-making regarding these issues.References: PRINCE2 7 Foundation materials on issue management and related documentation.

The Risk Register in PRINCE2 is a document used to detail all identified risks associated with the project, including both threats and opportunities. This register includes descriptions of each risk, their status, and the responses planned or taken to manage these risks, serving as a key tool for risk management throughout the project lifecycle.References: = PRINCE2 7 Foundation Training Manual and official PRINCE2 website documentation

The approval needed to replace a Stage Plan with an Exception Plan must come from the Project Board. This is because the Exception Plan is created when a Stage Plan is forecast to exceed its tolerance levels, and the Project Board is responsible for approving such significant changes in the project's direction or management.
References: PRINCE2 Foundation official documentation and study materials.