Which of the following is a method for client management using OAuth 2.0?

OpenID Connect Dynamic Client Registration is a method for client management using OAuth 2.0 because it allows for the dynamic registration of clients with an authorization server. This process provides a standardized way for clients to register themselves, retrieve sensitive information such as client credentials, and update their registration as needed without requiring manual intervention from the server administrators.

This approach enhances the flexibility and scalability of OAuth 2.0 implementations, particularly in environments where clients may frequently change or need to be added. By supporting dynamic client registration, OAuth 2.0 can accommodate diverse applications and clients more efficiently, allowing for better resource management and security practices.

In contrast, other options do not inherently relate to client management in the context of OAuth 2.0. Fetch API Key Management pertains to managing API keys rather than client registration or authentication processes. The Data Layer Access Token System is not a widely recognized method within the OAuth framework and does not specifically address client management. Lastly, the Client Message Authentication Scheme is focused on securing messages rather than managing client credentials or registrations under the OAuth 2.0 standard.