A task agent with approvals is the best design. This "human-in-the-loop" model directly satisfies the critical requirements for a regulated environment: all record updates are "approval-gated," ensuring a reviewer validates the agent's proposed actions before execution. This pattern inherently creates a complete audit trail of requests and approvals, supporting compliance and the principle of least privilege. It allows the agent to perform its tasks (triage, draft, update) while maintaining strict human oversight for sensitive operations, balancing automation with governance without adding new connectors (e.g., using built-in Power Automate approvals).

B. Autonomous agent executes actions without reviewer approval: This directly violates the "approval-gated" and "least privilege" requirements, making it unsuitable for a regulated environment.

C. Prompt-only drafting assistant: This design is too limited; it fails to meet the requirements to "triage inbound requests" and "update case records."

D. Single agent with shared tools: This describes an implementation detail, not a governance model. It does not guarantee that the necessary approval gates are in place.

1. Microsoft Copilot Studio Documentation. (2024). Generative actions with approvals. Microsoft Learn. Retrieved from https://learn.microsoft.com/en-us/microsoft-copilot-studio/nlu-generative-actions-approvals. (This document describes the specific pattern of requiring human approval before a Copilot action is executed).

2. Microsoft Power Automate Documentation. (2023). Create and test an approval workflow. Microsoft Learn. Retrieved from https://learn.microsoft.com/en-us/power-automate/get-started-approvals. (This details the underlying approval mechanism that can be integrated with a task agent).

3. Guidance, P. P. (2023). Implementing a secure environment strategy. Microsoft Power Platform Adoption Framework. Retrieved from https://learn.microsoft.com/en-us/power-platform/guidance/adoption/secure-environment-strategy. (Section on "Least privilege access" emphasizes the importance of such controls in secure designs).