Your organization has Compute Engine instances in us-east1, us-west2, and us-central1. Your organization also has an existing Cloud Interconnect physical connection in the East Coast of the United States with a single VLAN attachment and Cloud Router in us-east1. You need to provide a design with high availability and ensure that if a region goes down, you still have access to all your other Virtual Private Cloud (VPC) subnets. You need to accomplish this in the most cost-effective manner possible. What should you do?

A. 1. Configure your VPC routing in regional mode.
2. Add an additional Cloud Interconnect VLAN attachment in the us-east1 region, and configure a Cloud Router in us-east1. B. 1. Configure your VPC routing in global mode.
2. Add an additional Cloud Interconnect VLAN attachment in the us-east1 region, and configure a Cloud Router in us-east1. C. 1. Configure your VPC routing in global mode.
2. Add an additional Cloud Interconnect VLAN attachment in the us-west2 region, and configure a Cloud Router in us-west2. D. 1. Configure your VPC routing in regional mode.
2. Add additional Cloud Interconnect VLAN attachments in the us-west2 and us-central1 regions, and configure Cloud Routers in us-west2 and us-central1.