You create an integration between the Dataverse and Azure SQL database. You need to be sure that data is in-sync. 
What are two options you can use for data syncing and checking for the latest changes?

Answer options:

A.OpenAPI
B.Change tracking
C.Blank custom connector
D.Delta link
E.Postman Collection

Correct Answers: B and D 
To synchronize the data between the Dataverse and external system, you need to enable the Change tracking option (Number 3) for the tables you want to synchronize. You can find this option on the table settings blade (Number 1) under the "Create and update settings" section (Number 2). 

You can retrieve the data changes using the Delta links. The Delta links are the tool provided by the OData 4.0 specification. It works like the date and time tracking stamps. To see the table’s changes, you need to use a Web API and call the Dataverse entity using a special header key: Prefer with “odata.track-changes” as a value. In response, you will get the deltaLink token. You can use this token the next time when you want to see the changes since you run your query. 

All other options are incorrect. 
For more information about the Dataverse change tracking and data synchronization, please visit the below URLs: 

https://docs.microsoft.com/en-us/powerapps/developer/data-platform/use-change-tracking-synchronize-data-external-systems
https://docs.microsoft.com/en-us/learn/modules/common-data-service-web-api/8-change-tracking
https://docs.microsoft.com/en-us/powerapps/developer/data-platform/data-synchronization