Select three data source types in Azure that an indexer can use to crawl and load the search documents from.

Answer options:

A.hanadb
B.cosmosdb
C.azuretable
D.azuresql
E.oracledb

Correct Answers: B, C and D
Option A is incorrect. Here database is not a currently supported data source for Indexers in Azure.
Option B is correct. You can index data stored in Cosmos DB using Indexer in Azure Cognitive Search by passing the value as cosmosdb to the type variable of a POST or PUT statement.
Option C is correct. You can index data stored in Azure Table Storage using Indexer in Azure Cognitive Search by passing the value as azuretable to the type variable of a POST or PUT statement.
Option D is correct. You can index data stored in Azure SQL database or SQL managed instance using Indexer in Azure Cognitive Search by passing the value as azuresql to the type variable of a POST or PUT statement.
Option E is incorrect. Oracle database is not a currently supported data source for Indexers in Azure.
Reference:
To learn more about supported data sources for Indexers in Azure, use the links given below: 

https://docs.microsoft.com/en-us/azure/search/search-indexer-overview#supported-data-sources