You are updating an application that stores data on Azure and uses Azure Cosmos DB for storage. The application stores data in multiple documents associated wit...

You are updating an application that stores data on Azure and uses Azure Cosmos DB for storage. The application stores data in multiple documents associated with a single username.
The application requires the ability to update multiple documents for a username in a single ACID operation.
You need to configure Azure Cosmos DB.
Which two actions should you perform? Each correct answer presents part of the solution.
NOTE: Each correct selection is worth one point.

A. Create a collection sharded on username to store documents. B. Configure Azure Cosmos DB to use the Gremlin API. C. Create an unsharded collection to store documents. D. Configure Azure Cosmos DB to use the MongoDB API.