The correct answer is D because connecting to a Windows instance requires the installation of an RDP client, as GCP does not provide one. You must generate a Windows instance password for authentication, and the RDP protocol uses port 3389. Options A and B are incorrect because an external RDP client is necessary, and you cannot connect directly from the GCP console. Options B and C are incorrect because port 22 is designated for SSH, not RDP. For more details, refer to the GCP documentation on Connecting to Windows Instances.