Your subscription contains an Azure App Service app that uses the hostname https://www.contoso.com. You must configure a custom domain on Azure Front Door for www.contoso.com, and the custom domain must use a certificate issued by an allowed certification authority (CA). Which service or component should you include in the solution to supply or manage the required certificate?

Azure Key Vault is the correct choice because it securely stores and manages cryptographic keys, secrets, and SSL/TLS certificates, which is essential for custom domains on Azure Front Door. Front Door can directly integrate with Key Vault to retrieve and manage certificates for your custom domains, ensuring secure communication. An enterprise application in Azure AD is for managing application access and permissions, not certificates. AD CS is an on-premises certificate authority and not directly integrated with Azure Front Door for certificate management in this scenario. Azure Application Gateway is a web traffic load balancer that can manage certificates for its own listeners but is not the service used by Azure Front Door to source certificates for custom domains.