The correct answer is A. Add the Logs Writer role to the service account.
To use Cloud Logging, the service account attached to the Compute Engine instance must have the necessary permissions to write log entries. The Logs Writer role (roles/logging.logWriter) provides this permission.You can grant this role to the user-managed service account at the project, folder, or organization level1.
Private Google Access is not required for Cloud Logging, as it allows instances without external IP addresses to access Google APIs and services2.The default Compute Engine service account already has the Logs Writer role, but it is not a recommended practice to use it for user applications3.Exporting the service account key and configuring the agents to use the key is not a secure way of authenticating the service account, as it exposes the key to potential compromise4.
References:
1:Access control with IAM | Cloud Logging | Google Cloud
2: Private Google Access overview | VPC | Google Cloud
3: Service accounts | Compute Engine Documentation | Google Cloud
4: Best practices for securing service accounts | IAM Documentation | Google Cloud

The best option for giving developers the ability to test the latest revisions of the service before the service is exposed to customers is to run the gcloud run deploy booking-engine --no-traffic --tag dev command and use the https://dev----booking-engine-abcdef.a.run.app URL for testing. The gcloud run deploy command is a command that deploys a new revision of your service or updates an existing service. By using the --no-traffic flag, you can prevent any traffic from being sent to the new revision. By using the --tag flag, you can assign a tag to the new revision, such as dev. This way, you can create a new revision of your service without affecting your customers. You can also use the tag-based URL (e.g., https://dev----booking-engine-abcdef.a.run.app) to access and test the new revision.

https://cloud.google.com/billing/docs/how-to/export-data-bigquery

Comprehensive and Detailed 150 to 200 words of Explanation From Google Cloud DevOps guides documents:
Google Cloud's recommended practice for scalable, multi-cluster monitoring is Google Cloud Managed Service for Prometheus (GMP). This service is a fully managed, multi-cloud-capable solution built on top of Monarch (the same globally scalable time-series database Google uses internally). By using managed collection, GKE clusters automatically deploy collectors that scrape metrics without the operational overhead of managing a manual Prometheus server, scaling, or long-term storage (sharding).
This solution satisfies the "centralized and scalable" requirement because GMP allows you to query data across multiple projects and clusters using PromQL, which provides the flexible query language requested.
While the Ops Agent (Option C) is useful for VM-based workloads, GMP is the purpose-built solution for Kubernetes environments. Standard sidecar deployments (Option A) or self-managed admin clusters (Option D) introduce significant administrative toil and fail to leverage the global scale and high availability of the Cloud Monitoring backend. By centralizing metrics in Metrics Explorer, SRE teams gain a unified view of system health, making it easier to define SLOs and manage incidents across a complex microservices landscape.

Your application runs on Google Cloud Platform (GCP). You need to implement Jenkins for deploying application releases to GCP. You want to streamline the release process, lower operational toil, and keep user data secure. What should you do?
https://plugins.jenkins.io/google-compute-engine/