You have an Azure Front Door instance named FD1 that is protected by using Azure Web Application Firewall (WAF). FD1 uses a frontend hast named app1.contoso.com...

You have an Azure Front Door instance named FD1 that is protected by using Azure Web Application Firewall (WAF).
FD1 uses a frontend hast named app1.contoso.com to provide access to Azure web apps hosted in the East US Azure region and the West US Azure region.
You need to configure FD1 to block requests to app1.contoso.com from all countries other than the United States.
What should you include in the WAF policy?

A. a custom rule that uses a match rule B. a frontend hast association C. a custom rule that uses a rate limit rule D. a managed rule set