Which of the following is compatible with Local, Active Directory, and LDAP identity stores?

The correct choice for compatibility with Local, Active Directory, and LDAP identity stores is Basic Authentication. Basic Authentication is a straightforward authentication method that allows users to access resources by providing a username and password. This mechanism is widely supported across various identity stores including local accounts, Active Directory, and LDAP systems.

In this context, Local identity stores are internal to the application, Active Directory is Microsoft's directory service for Windows domain networks, and LDAP is a protocol for accessing directory services. Basic Authentication works seamlessly with all of these because it directly uses the credentials stored within those systems.

Other options may have specific use cases, but they do not provide the same level of broad compatibility with the mentioned identity stores as Basic Authentication does. SAML (Security Assertion Markup Language) is primarily used for Single Sign-On (SSO) scenarios and requires a federation or identity provider to function, which may not be directly compatible without additional configurations. Kerberos is a secure authentication protocol but is more complex and typically tied to specific environments. Site SAML refers to a configuration that may also require specific configurations relating to SSO and does not have the straightforward compatibility that Basic Authentication provides.