Which authentication configuration lets a Container App require Azure AD sign-in without any code changes?

1. ✓ A Built-in authentication (Easy Auth) with the Microsoft identity provider (correct answer)
2. B A custom OAuth middleware in the container
3. C An API Management policy
4. D Client certificates only

Shortcut: Container Apps supports built-in authentication that intercepts requests before they reach the container, handling the OIDC flow and injecting identity headers.