Exam Professional Cloud Developer topic 1 question 229 discussion

Cloud Build Pub/Sub triggers enable you to execute builds in response to Google Cloud events published over Pub/Sub. You can use information from a Pub/Sub event to parameterize your build and to decide if a build should execute in response to the event. Pub/Sub triggers can be configured to listen to any Pub/Sub topic.

Option A is not better than Option C because it involves using Cloud Build instead of Cloud Functions for the deployment promotion process. While Cloud Build is a powerful tool for building and testing applications, it is generally not recommended for triggering automated tasks in response to events like the successful deployment of an application to a cluster. In Option A, the Cloud Build trigger listens for SUCCEEDED Pub/Sub messages from the clouddeploy-operations topic, and then promotes the application to the Test cluster as part of the Cloud Build pipeline. This approach involves using a more complex and less scalable infrastructure than using a serverless function like Cloud Functions. On the other hand, Option C uses a Cloud Function to promote the application, which is a more streamlined, scalable, and event-driven solution. Cloud Functions are designed specifically for triggering automated tasks in response to events, making them a better choice for this type of use case.

https://cloud.google.com/functions/docs/calling/pubsub mhh i see why it could be C