HOTSPOT
You plan to deploy four Infrastructure as a Service (IaaS) virtual machines in Azure. All IaaS virtual machines
will reside on the same IP subnet.
You need to design an Azure virtual network that can accommodate the deployment. The design must meet the
following requirements:
Minimize the size of the IP subnet.
Provide the ability to restrict both internal and Internet traffic.
Ensure that the IP addresses of the virtual machines remain the same.
What should you include in the design? To answer, select the appropriate options in the answer area.
Hot Area:
Answer: 
Explanation:
Not /29.
/29 would normally provide up to 8 IP addresses which should be enough for four VMs. However, Azure
reserves five IP addresses so for four VMs, you need a subnet with at least 9 IP addresses.
is it /28 or /29 ?
29 would normally provide up to 8 IP addresses which should be enough for four VMs. However, Azure reserves five IP addresses so for four VMs, you need a subnet with at least 9 IP addresses.
Keep in mind that Azure reserves 5 private IP addresses from each subnet that cannot be used: the first and last addresses of the address space (for the subnet address, and multicast) and 3 addresses to be used internally (for DHCP and DNS purposes).
https://docs.microsoft.com/en-us/azure/virtual-network/virtual-network-vnet-plan-design-arm