Which of the following data connector uses Azure Policy to apply a common diagnostic settings configuration to a collection of resources of a single type?

Answer options:

A.Azure Key Vault
B.Azure Active Directory
C.Azure Firewall
D.Azure Defender

Correct Answer: A 
Azure Policy allows you to apply a common set of diagnostics logs settings to all (current and future) resources of a particular type whose logs you want to ingest into Azure Sentinel. 
As of now 3 data connectors - Azure Key Vault, Azure Kubernetes Service and Azure SQL Databases have now been offered to be managed by Azure Policy. 
Reference: 

https://docs.microsoft.com/en-us/azure/sentinel/data-connectors-reference