You must deploy five virtual machines into a single virtual network subnet. Each VM will have both a public and a private IP address, and all VMs must use identical inbound and outbound security rules. What is the minimum number of network/security groups required for this setup?

The correct answer is 1. A single Network Security Group (NSG) can be associated with the subnet. When an NSG is associated with a subnet, its rules apply to all virtual machines within that subnet. Since all five VMs require identical inbound and outbound security rules, one NSG is sufficient and most efficient. Option 4 is incorrect because you don't need a separate NSG for each VM. Option 3 and 2 are also incorrect as they suggest more NSGs than necessary. A single NSG at the subnet level simplifies management and ensures consistent security policies for all VMs in that subnet.