Activating a failover database server ensures that financial transactions can continue processing with minimal downtime during a primary database server's hardware failure. Failover servers are typically synchronized and ready to take over immediately, which is the most appropriate course of action in this context. While restoring from backups is a valid recovery option, it may not support immediate transaction continuity and could result in data loss for any transactions that occurred after the last backup. Requesting technical assistance and performing diagnostics are both proactive measures for resolving the issue, but they will not ensure the continuation of financial transactions during the interim period.