Thousands of suppliers upload files. Requirements: suppliers can access only their own data, write access limited to 30 minutes, delete objects older than 45 days, and minimal maintenance. Which two strategies should you use? (Choose two.)

A lifecycle policy automatically deletes Cloud Storage objects after 45 days, meeting the requirement for minimal maintenance and ensuring data hygiene. Signed URLs grant temporary, time-limited write access to specific objects, allowing suppliers to upload their data without needing permanent credentials or broader bucket permissions, satisfying the 30-minute write access and "access only their own data" requirements. Setting up an SFTP server would involve significant maintenance and management overhead, contrary to the "minimal maintenance" requirement. A Cloud Function for deletion is less efficient and more complex than a native lifecycle policy. A script deleting buckets older than 45 days is incorrect; the requirement is to delete objects, not entire buckets, and it would also be a manual, high-maintenance solution.