Answer: Hit-level, session-level, or user-level scope
Explanation: Dimensions and Custom metrics are default dimensions and metrics in any Analytics account. You can use them to collect and analyze data that Analytics doesn't automatically track.
dimensions and metrics allow you to combine Analytics data with non-Analytics data, e.g. CRM data.
The scopes determines which hits will be associated with a particular custom-dimension value and they include Hit-level, session-level, or user-level scope