Splunk users are assigned roles.

This is the correct answer because roles determine the level of access that users have to the Splunk platform and the tasks that they can perform on the platform1. Roles can contain one or more capabilities that provide access to specific parts of the Splunk platform, such as searching, indexing, alerting, and so on2. Roles can also specify which indexes that a user can search and which indexes are searched by default1.