* Run gcloud builds submit tag gcr.io/img-278322/acme_track_n_trace:v1. is the right answer.
This command correctly tags the image as acme_track_n_trace:v1 and uploads the image to the img-278322 project.
Ref: https://cloud.google.com/sdk/gcloud/reference/builds/submit

https://cloud.google.com/compute/docs/access/service-
accounts#associating_a_service_account_to_an_instance

Explanation
Folders are nodes in the Cloud Platform Resource Hierarchy. A folder can contain projects, other folders, or a combination of both. Organizations can use folders to group projects under the organization node in a hierarchy. For example, your organization might contain multiple departments, each with its own set of Google Cloud resources. Folders allow you to group these resources on a per-department basis. Folders are used to group resources that share common IAM policies. While a folder can contain multiple folders or resources, a given folder or resource can have exactly one parent.
https://cloud.google.com/resource-manager/docs/creating-managing-folders

A is not correct because a Datastore database is not designed for file storage.
B is correct because buckets can be multi-regional and have lifecycle management.
C is not correct because disks are generally ephemeral for virtual machines in managed instance groups.
D is not correct because content would be restricted to a single region for all international users.