The scenario that would most significantly restrict the areas where internal audit could perform assurance services is if the internal audit activity reports administratively to the chief financial officer (CFO). Reporting to the CFO could impair the perceived independence of the internal audit activity because the CFO is typically responsible for the financial and operational aspects of the organization that internal audit frequently assesses.
This relationship could create a conflict of interest and limit the scope of audits that can be performed impartially.References: The Institute of Internal Auditors (IIA) - International Standards for the Professional Practice of Internal Auditing

In creating a fraud risk matrix, an internal auditor would most likely include fraud scenarios along with the relevant risks associated with each scenario. This approach allows for a detailed analysis of specific fraudulent acts that could occur and the risk levels pertaining to different areas of operation within the branch. This is essential for identifying and prioritizing fraud risks and helps in designing or enhancing controls to mitigate these risks effectively.References: IIA guidance on fraud risk management.

An assessment of performance management practices and the establishment of key performance indicators directly relates to organizational governance, as these elements are integral in defining and measuring how organizational goals are achieved, which is a key aspect of governance. Internal auditors assessing these areas contribute significantly to evaluating and improving the governance framework within the organization.References: IIA Practice Advisory on Governance