Microsoft 365 Copilot agents operate within the security, compliance, and identity boundaries of a Microsoft 365 tenant. Custom agents created in the Microsoft 365 Copilot app are governed by organizational policies, role-based access control, and Microsoft Entra ID authentication.

According to Microsoft AI Business Professional guidance, Copilot agents are designed for enterprise use and are shared within the organization unless administrators configure broader sharing capabilities. External sharing with personal Microsoft accounts or arbitrary email addresses is not supported by default due to security, data protection, and compliance requirements.

Because the agent in this scenario interacts with organizational data such as client emails, project milestones, and internal reports, access must remain restricted to authenticated users within the same tenant. This ensures that sensitive business information remains protected and that data access respects existing permissions.

Therefore, the agent can be shared only with people in your organization, making option D the correct answer.