To create a tag, the user must have the tag capability associated with their user role. The tag capability allows the user to create, edit, and delete tags. The user does not need to identify a field:value pair, have the Power role, or be able to edit the sourcetype the tag applies to.ReferencesSee Define and manage tags in Settings and
[About capabilities] in the Splunk Documentation.

"Calculated fields can reference all types of field extractions and field aliasing, but they cannot reference lookups, event types, or tags."

The time range specified for a historical search defines the amount of data fetched from the index matching that time range2. A historical search is a search that runs over a fixed period of time in the past2. When you run a historical search, Splunk searches the index for events that match your search string and fall within the specified time range2. Therefore, option B is correct, while options A and C are incorrect because they are not what the time range defines for a historical search.

The command sourcetype=access_combined | transaction JSESSIONID does three things:
It filters the events by the sourcetype access_combined, which is a predefined sourcetype for Apache web server logs.
It groups the events by the field JSESSIONID, which is a unique identifier for each user session.
It creates a single event from each group of events that share the same JSESSIONID value. This single event will have some additional fields created by the transaction command, such as duration, eventcount, and startime.
Therefore, the statements B, C, and D are true.