What file is used for maintaining authentication settings in Splunk?

The correct answer is A, authentication.conf, which is the file specifically designated for managing authentication settings in Splunk. This configuration file contains directives that control how users authenticate to the Splunk instance, including settings for various authentication methods, such as LDAP, SAML, or local authentication.

Utilizing authentication.conf allows for the centralized management of user credentials and authentication processes, ensuring that Splunk can effectively verify user identities when they attempt to access the system. This is crucial for maintaining security and ensuring that only authorized users have access to sensitive data.

In comparison, authorize.conf is focused on managing user roles and their access permissions, server.conf primarily handles server settings and configurations, and rest.conf is used for configuring RESTful API settings. Therefore, while each of these configuration files plays an important role within Splunk, authentication.conf is singularly responsible for maintaining the authentication settings specifically.