The answer is B. A VPN tunnel. A VPN tunnel is a secure and encrypted connection between two networks over a public network, such as the Internet. A VPN tunnel can help protect data in transit by encrypting it before it leaves the company's network and decrypting it when it reaches the public cloud service provider. A VPN tunnel can also authenticate the endpoints and verify the integrity of the data. Some possible sources of information about VPN tunnels are: What is a VPN Tunnel? | Fortinet: This page explains what a VPN tunnel is, how it works, and what benefits it provides. VPN Gateway: Create a Site-to-Site connection using a VPN gateway | Microsoft Docs: This page shows how to create a site-to-site connection using a VPN gateway in Azure. [Cloud VPN overview | Google Cloud]: This page provides an overview of Cloud VPN, a service that creates secure and reliable VPN tunnels to Google Cloud.