You need to set up duplicate detection rules for a Dataverse table. But when you create a new rule, you cannot find your table in the dropdown list under the Duplicate Detection Rule Criteria section on the Duplicate Detection Rules console . 
What should you do?

Answer options:

A.Change your role to a System Customizer
B.Enable table’s duplicate detection
C.Change your role to a System Administrator
D.Enable a duplicate detection for created and uploaded records
E.Add new duplicate detection job

Correct Answer: B 
In the Dataverse, Duplicate detection is enabled by default for the Organization. 
The Dataverse provides the three duplicate detection services: Duplicate detection jobs — creates scheduled jobs for duplicates detection.
Duplicate detection rules — defines duplicate detection rules for tables (entities) and columns (fields)
 matching.
Duplicate detection settings — sets the default duplicate detection settings for an organization.
Before you create a duplicate detection rule, you need to enable the Duplicate detection settings for your table (entity). 

After that, you will see this table in the dropdown list under the Duplicate Detection Rule Criteria section on the Duplicate Detection Rules console. 

All other options are incorrect. 
For more information about the Dataverse duplicate detection, please visit the below URLs: 

https://docs.microsoft.com/en-us/power-platform/admin/set-up-duplicate-detection-rules-keep-data-clean
https://docs.microsoft.com/en-us/power-platform/admin/turn-duplicate-detection-rules-off-whole-organization