Exam AZ-303 topic 2 question 8 discussion

certainly C

yes.C is right answer.

But the question says they are not accessible from the internet. Why does it depend on public DNS when it is not accessible from the web?

Yes, you can find confirmation on the Fron Door Faq Page: "Can we deploy Azure Load Balancer behind Front Door? Azure Front Door needs a public VIP or a publicly available DNS name to route the traffic to. Deploying an Azure Load Balancer behind Front Door is a common use case. ... What resources are supported today as part of backend pool? Backend pools can be composed of Storage, Web App, Kubernetes instances, or any other custom hostname that has public connectivity. Azure Front Door requires that the backends are defined either via a public IP or a publicly resolvable DNS hostname. Members of backend pools can be across zones, regions, or even outside of Azure as long as they have public connectivity." https://docs.microsoft.com/en-us/azure/frontdoor/front-door-faq

Answer is C, because Azure Front Door Requires Public VIP or publicly available DNS to route traffic to. https://docs.microsoft.com/en-us/azure/frontdoor/front-door-faq

You're right. The statement "Currently, the virtual machines are inaccessible from the internet." is just to throw us off the real question. The question does not ask for us to make the machines accessible from the internet. We "need to use Azure Front Door to load balance requests for App1 across all the virtual machines", all of this will happen internally. So I will go with B

B : Look at the decision tree https://docs.microsoft.com/en-us/azure/architecture/guide/technology-choices/load-balancing-overview?toc=%2fazure%2ffrontdoor%2fstandard-premium%2ftoc.json and read about IaaS definition it says internal load balancer. So, using B is still possible.