You plan to deploy several Azure virtual machines.
You need to control the ports that devices on the internet can use to access the virtual machines.
What should you use?
A . an Azure Active Directory (AzureAD) role
B . an Azure key vault
C . an Azure Active Directory group
D . a network security group (NSG)
Answer: D
Explanation: https://docs.microsoft.com/en-us/azure/virtual-network/security-overview