Explanation

Box 1: DTU
Scenario:
* The 30 new databases must scale automatically.
* Once all requirements are met, minimize costs whenever possible.
You can configure resources for the pool based either on the DTU-based purchasing model or the vCore-based purchasing model.
In short, for simplicity, the DTU model has an advantage. Plus, if you're just getting started with Azure SQL Database, the DTU model offers more options at the lower end of performance, so you can get started at a lower price point than with vCore.
Box 2: An Azure SQL database elastic pool
Azure SQL Database elastic pools are a simple, cost-effective solution for managing and scaling multiple databases that have varying and unpredictable usage demands. The databases in an elastic pool are on a single server and share a set number of resources at a set price. Elastic pools in Azure SQL Database enable SaaS developers to optimize the price performance for a group of databases within a prescribed budget while delivering performance elasticity for each database.
Reference:
https://docs.microsoft.com/en-us/azure/azure-sql/database/elastic-pool-overview
https://docs.microsoft.com/en-us/azure/azure-sql/database/reserved-capacity-overview

Explanation:

Reference:
https://docs.microsoft.com/en-us/azure/azure-sql/database/single-database-create-arm-template-quickstart Basic Concept: This question tests configure and manage automation of tasks in the DP-300 exam context.
The correct choice is determined by the exact service boundary and operational requirement stated in the scenario.
Why the selected answer is Correct: The selected values fit this scenario because they apply the required Azure SQL configuration at the correct scope and sequence: You have an Azure subscription.
Why the alternate choices are Wrong: The alternate selections apply to different administrative stages or different scopes. In a hotspot or drag-drop task, order and scope are part of the answer, so a technically valid Azure feature can still be wrong if it is placed in the wrong step.

Reference:
https://azure.microsoft.com/pricing/details/database-migration/
https://docs.microsoft.com/en-us/azure/dms/tutorial-sql-server-azure-sql-online

Explanation

https://learn.microsoft.com/en-us/azure/app-service/tutorial-connect-msi-sql-database?tabs=windowsclient%2Ce