The scenario requires a scalable solution where a central team manages the network while allowing 100+ teams to use separate projects. Shared VPC is designed for this purpose. In a Shared VPC setup, the host project (managed by the central team) contains the VPC network, and service projects (team-specific projects) attach to it. This centralizes network control and scales efficiently as new service projects can be added without reconfiguring the network. Option B correctly configures the VPC in the host project, aligning with centralized management. Options C and D are incorrect because VPC peering doesn't scale well with 100+ projects, and placing the VPC in service projects (D) decentralizes control. Policy-based Routing (A) is unrelated to cross-project network sharing.