You were the first person in your team who created the first app in Power Apps studio in Teams. 
What did Microsoft Team create for your app automatically?

Answer options:

A.A generated Power Apps app
B.Dataverse for Teams database
C.Dataverse database for Power Apps environment
D.A new Power Apps team

Correct Answer: B 
When you are the first on the team to create a Power Apps app in Teams, Microsoft Teams creates a new Power Platform environment with the type of "Microsoft Teams" (Number 1) and association to your Microsoft Teams team (Number 2). 
Microsoft Teams also provisions the Dataverse for Teams database. This database differs from the Power Platform Dataverse database. It is limited only to Teams and stores information that supports Power Apps apps created and running in Teams. 
You can access these apps outside of Teams in a web browser, but they would have some limitations because of the Dataverse for Teams scope. If you want to remove these limitations, you need to upgrade the Dataverse for Teams to the Power Platform Dataverse environment (Number 3). You can do this in the Power Platform admin center. 

All other options are incorrect. 
For more information about Power Apps apps created in Microsoft Teams, please visit the below URLs: 

https://docs.microsoft.com/en-us/powerapps/teams/create-first-app
https://docs.microsoft.com/en-us/powerapps/teams/create-apps-overview
https://docs.microsoft.com/en-us/power-platform/admin/about-teams-environment