You plan to use Microsoft Azure Data factory to copy data daily from an Azure SQL data warehouse to an
Azure Data Lake Store.
You need to define a linked service for the Data Lake Store. The solution must prevent the access token from
expiring.
Which type of authentication should you use?

A.
OAuth

B.
service-to-service

C.
Basic

D.
service principal

Explanation:
https://docs.microsoft.com/en-gb/azure/data-factory/v1/data-factory-azure-datalake-connector#azure-data-lakestore-linked-service-properties