You have an Azure subscription named Sub1 that contains the virtual machines shown in the following table. 

You need to ensure that the virtual machines in RG1 have the Remote Desktop port closed until an authorized user requests access. What should you configure? 

Answer options:

A. Azure Active Directory (Azure AD) Privileged Identity Management (PIM)
B. an application security group
C. Azure Active Directory (Azure AD) conditional access
D. just in time (JIT) VM access

D

Just-in-time (JIT) virtual machine (VM) access can be used to lock down inbound traffic to your Azure VMs, reducing exposure to attacks while providing easy access to connect to VMs when needed. Note: When just-in-time is enabled, Security Center locks down inbound traffic to your Azure VMs by creating an NSG rule. You select the ports on the VM to which inbound traffic will be locked down. These ports are controlled by the just-in-time solution. When a user requests access to a VM, Security Center checks that the user has Role-Based Access Control (RBAC) permissions that permit them to successfully request access to a VM. If the request is approved, Security Center automatically configures the Network Security Groups (NSGs) and Azure Firewall to allow inbound traffic to the selected ports and requested source IP addresses or ranges, for the amount of time that was specified. After the time has expired, Security Center restores the NSGs to their previous states. Those connections that are already established are not being interrupted, however. Reference: https://docs.microsoft.com/en-us/azure/security-center/security-center-just-in-time