You have an Azure subscription that contains an Azure App Service app. The app uses a URL of https://www.contoso.com.

You need to use a custom domain on Azure Front Door for www.contoso.com. The custom domain must use a certificate from an allowed certification authority (CA).

What should you include in the solution?

A. an enterprise application in Azure Active Directory (Azure AD)

B. Active Directory Certificate Services (AD CS)

C. Azure Key Vault

D. Azure Application Gateway

Reference:
https://docs.microsoft.com/en-us/azure/frontdoor/front-door-custom-domain-https