A customer has a requirement for Disaster Recovery for compliance within their industry. Theyhave an RPO of 4 hours and an RTO of 24 hours. Cost is a consideration. What is the most costeffective DR implementation？（）

• A、a disk-to-disk backup solution keeping all storage in the data center
• B、a backup solution that includes magnetic tape that is shipped to an off-site storage facility
• C、a less powerful copy environment at a hot site with asynchronous mirroring and cluster technology
• D、an exact copy of the primary environment at a hot site with remote mirroring and cluster technology