Which of the following can be used for this requirement?

Your company has an Azure Web App that runs via the Premium App Service Plan. A development team will be using the Azure Web App. You have to configure the Azure Web app so that it can fulfil the below requirements.

Provide the ability to switch the web app from the current version to a newer version

Provide developers with the ability to test newer versions of the application before the switch to the newer version occurs

Ensure that the application version can be rolled back

Minimize downtime

Which of the following can be used for this requirement?
A . Create a new App Service Plan
B. Make use of deployment slots
C. Map a custom domain
D. Backup the Azure Web App

Answer: B