Your development team is using Cloud Build to promote a Node.js application built on App Engine from your staging environment to production. The application relies on several directories of photos stored in a Cloud Storage bucket named webphotos-staging in the staging environment. After the promotion, these photos must be available in a Cloud Storage bucket named webphotos-prod in the production environment. You want to automate the process where possible. What should you do?

A. Manually copy the photos to webphotos-prod. B. Add a startup script in the application's app.yami file to move the photos from webphotos-staging to webphotos-prod. C. Add a build step in the cloudbuild.yaml file before the promotion step with the arguments:

D. Add a build step in the cloudbuild.yaml file before the promotion step with the arguments: