NetApp Cloud Volumes Service (CVS) for Google Cloud is deployed within a dedicated, NetApp-managed Virtual Private Cloud (VPC). To allow Google Compute Engine instances and other resources within a customer's VPC to access and mount the provisioned volumes, a direct, private network connection is required. This is achieved by establishing a VPC Peering connection between the customer's VPC and the NetApp service VPC. This peering allows the two networks to communicate using internal, private IP addresses as if they were part of the same network, which is a mandatory step for service provisioning and access.

A. Vnet Peering: This is the terminology for connecting virtual networks (Vnets) in Microsoft Azure, not Google Cloud Platform.

B. Subnet Delegation: This is a feature primarily associated with Microsoft Azure for dedicating a subnet to a specific platform service.

D. VPN Gateway: A VPN Gateway creates a secure connection over the public internet, typically for hybrid cloud, and is not the required method for direct, private connectivity within Google Cloud for this service.

1. NetApp Cloud Volumes Service for Google Cloud Documentation, "Networking considerations for Cloud Volumes Service for Google Cloud". The documentation states, "To allow communication between your Google Cloud project and Cloud Volumes Service, you must create a VPC peering connection. The peering connection lets resources in your VPC communicate with the Cloud Volumes file systems by using internal IP addresses."

2. Google Cloud Documentation, "VPC Network Peering overview". This document defines the technology: "Google Cloud VPC Network Peering connects two Virtual Private Cloud (VPC) networks so that resources in each network can communicate with each other... The VPC networks can be in the same project, different projects of the same organization, or different projects of different organizations." This confirms VPC Peering as the mechanism for connecting separate VPCs for private communication.