You plan to deploy an Azure Virtual Network NAT gateway (Gateway1) to VNet1. VM1 and VM2 must each use their own public IP addresses to access the internet, and administrative effort should be minimized. What is the minimum number of subnets that must exist in VNet1 to allow deployment of Gateway1 given these requirements?

The correct answer is 4. Each VM needs its own public IP address for internet access, and a NAT Gateway provides outbound connectivity for an entire subnet. Therefore, to ensure VM1 and VM2 each use a distinct public IP, they must reside in separate subnets. This means you need at least two subnets for the VMs. Additionally, a NAT Gateway requires its own dedicated subnet for deployment. Finally, a separate subnet is needed for the NAT Gateway's public IP address resource. Thus, the minimum required subnets are: one for VM1, one for VM2, one for the NAT Gateway itself, and one for the public IP resource, totaling four.