Which of the following disaster recovery strategies has the highest cost and shortest recovery time?

A warm site has some hardware and connectivity pre-installed but requires additional configuration and data restoration from backups before becoming operational, resulting in moderate recovery times and moderate costs compared to a hot site.

A hot site maintains fully configured and operational systems with current data, often achieved through continuous replication, so that operations can fail over within minutes or even seconds of a disaster. This near-zero Recovery Time Objective (RTO) comes at the highest cost because the organization must pay to operate and maintain a complete duplicate infrastructure at all times, even when it is not needed.

A cold site provides only basic facilities such as power, cooling, and physical space with no pre-installed equipment, resulting in the lowest cost but the longest recovery time since all hardware must be procured, installed, and configured after a disaster.

A co-location site provides physical data center space, power, and connectivity for the organization to install its own equipment - its cost and recovery time depend entirely on how the organization configures and populates it, and it is not inherently the highest-cost or fastest-recovery option.