Which disaster recovery option is the LEAST expensive? (CLF-C02)

Correct answer: C. Backup and restore.
Backup and restore is a disaster recovery option that involves regularly backing up data and systems, and restoring them in the event of a disaster. This option is typically the least expensive because it doesn't require maintaining a duplicate infrastructure or keeping systems in a warm or hot state.

Here's a rough estimate of the costs associated with each option, from lowest to highest:
Backup and restore: This option typically requires only storage costs for backups, which can be relatively low.
Pilot light: This option requires maintaining a minimal infrastructure in the cloud, which can be more expensive than backup and restore.
Warm standby: This option requires maintaining a duplicate infrastructure that is partially running, which can be more expensive than pilot light.
Multisite: This option requires maintaining a fully redundant infrastructure, which can be the most expensive option.