You have configured an Azure Sentinel solution and wish to proactively look for security threats using Hunting in the Sentinel Portal. Which query language must you use when searching for threats?

Answer options:

A.Transact-SQL
B.Gremlin query language
C.MySQL
D.Kusto query language

Correct Answer: D 
Hunting in Azure Sentinel is based on Kusto query language.This is a read-only request to process data and return results. The request is stated in plain text, using a data-flow model designed to make the syntax easy to read, author, and automate. designed to make the syntax easy to read, author, and automate. 

Option A is incorrect. T-SQL (Transact-SQL) is a set of programming extensions from Sybase and Microsoft that add several features to the Structured Query Language. Some of the tools that use T-SQL are SQL Server Management Studio, Azure Data Studio, SQL Server Data Tools and sqlcmd.
Option B is incorrect. Gremlin is a query language used to retrieve data from and modify data in the applications graph. Azure Cosmos DB supports Gremlin.
Option C is incorrect. MySQL is an open source relational database management system with a client-server model. Azure Database for MySQL supports MySQL.
Reference: 
To know more about Azure Sentinel Hunting, please refer to the link below: 

https://docs.microsoft.com/nb-no/azure/sentinel/hunting