The correct answer is B because Google Transfer Appliance is specifically designed for large-scale offline data movement into Google Cloud when network bandwidth is limited or impractical. Google documents it as a high-capacity storage appliance that customers load on-premises and then securely ship to a Google upload facility, where the data is transferred into Cloud Storage. That matches the scenario exactly: the site is isolated, the bandwidth is constrained, and the volume is extremely large at 600 TB. In CHFI v11, cloud forensics includes understanding cloud platforms and evidence acquisition approaches, so recognizing the difference between online transfer services and offline shipping methods is important. Data Transfer Services generally rely on network-based transfers and are not the best choice when direct connectivity is a bottleneck. Cloud Storage for Firebase is unrelated to bulk evidence migration, and Backup and DR is intended for protection and recovery workflows rather than secure offline ingestion. When the exam scenario stresses secure shipment of very large datasets into Google Cloud without relying on available bandwidth, Transfer Appliance is the only option that cleanly fits the operational requirement.