An IaaS application has a two-hour RTO and four-hour RPO. The application takes one hour to back up its data or restore from a local backup file. A systems administrator is tasked with configuring the backup policy. Which of the following should the administrator configure to achieve the application requirements with the LEAST cost?

A. Back up to long-term storage every night.
B. Back up to object storage every three hours.
C. Back up to long-term storage every four hours.
D. Back up to object storage every hour.