You host VMs in us-central1-a and must tolerate a single zone failure with no downtime while minimizing cost. What should you do?

To tolerate a single zone failure with no downtime and minimize cost, you should deploy your application across at least two zones within the same region. Creating Compute Engine resources in us-central1-b and balancing load across us-central1-a and us-central1-b ensures that if one zone fails, the other can continue serving traffic. This provides high availability and fault tolerance at a lower cost than multi-region deployments. A Managed Instance Group in a single zone (us-central1-a only) does not protect against zone failures. An HTTP(S) Load Balancer is a component that would be used with the multi-zone deployment, not a solution on its own. Relying on regular backups and restoration would lead to significant downtime, which violates the "no downtime" requirement.