A Cloud Storage bucket with Cloud CDN enabled has cached objects under prefix folder-a. To remove cached copies for all objects with that prefix using the minimum commands, what should you do?

Issuing a cache invalidation command with the pattern /folder-a/ directly tells Cloud CDN to remove all cached objects matching that prefix. This is the most efficient and direct method for targeted cache removal. Adding a lifecycle rule on the storage bucket manages object deletion or archiving within Cloud Storage, but it does not directly control Cloud CDN's cache. Ensuring objects are not publicly shared is a security measure and doesn't clear the cache. Disabling and re-enabling Cloud CDN would clear the entire cache for the bucket, which is overkill and not targeted to a specific prefix, and also introduces downtime.