You manage three Google Cloud projects with the Cloud Monitoring API enabled. You want to follow Google-recommended practices to visualize CPU and network metrics for all three projects together. What

This option is identical to B, describing the correct method for aggregating and visualizing metrics across multiple projects in Cloud Monitoring.

Google Cloud Monitoring allows you to create a 'scoping project' which can monitor resources from multiple associated Google Cloud projects. By creating a Cloud Monitoring Dashboard within this scoping project, you can add widgets that display metrics (like CPU and network usage) from any of the projects monitored by that workspace, providing a consolidated view across all three projects.

Creating a service account and granting viewer roles is for programmatic access control to projects, not the mechanism for aggregating and visualizing metrics from multiple projects in a single monitoring view.

Creating a fourth Google Cloud project is not inherently the step to aggregate monitoring; while that project *could* become the scoping project, the key action is the dashboard setup within Cloud Monitoring (and project association), not just creating a project.