Explanation
The tag=Priv* search will return events containing a tag named Privileged, as well as any other tag that starts with Priv. The asterisk (*) is a wildcard character that matches zero or more characters. The other searches will not match the exact tag name.

Explanation/Reference: https://docs.splunk.com/Documentation/Splunk/8.0.3/Knowledge/FXSelectMethodstep

Reference:
A tag is a descriptive label that you can apply to one or more fields or field values in your events2. You can use tags to simplify your searches by replacing long or complex field names or values with short and simple tags2. To search for a tag associated with a value on a specific field, you can use the following syntax: tag::<field>=<tagname>2. For example, tag::status=error will search for events where the status field has a tag named error. Therefore, option D is correct, while options A, B and C are incorrect because they do not follow the correct syntax for searching tags.

Explanation
This is because an event type is a knowledge object that assigns a user-defined name to a set of events that match a specific search criteria. For example, you can create an event type named successful_purchase for events that have sourcetype=access_combined, status=200, and action=purchase. Then, you can use eventtype=successful_purchase as a search term to find those events. You can also use event types to create alerts, reports, and dashboards. You can learn more about event types from the Splunk documentation1. The other options are incorrect because they do not describe what an event type is. A log level measurement is a field that indicates the severity of an event, such as info, warn, or error. A knowledge object that is applied before fields are extracted is a source type, which identifies the format and structure of the data. Either a log, a metric, or a trace is a type of data that Splunk can ingest and analyze, but not an event type.