A local disaster such as fire or flood is, by definition, geographically confined; it damages or destroys everything physically present at the affected site, regardless of how many separate devices or storage systems are located there. The only way to guarantee that a copy of the data survives such an event is to ensure that at least one copy exists somewhere geographically removed from the risk, either at a genuinely remote physical site or in a cloud provider's data center located outside the affected area. This satisfies the core disaster recovery principle that protection copies must not share fate with the primary site. Storing backup data on the same device as the original (B) provides no protection at all against any failure, let alone a site-wide disaster, since both copies would be destroyed simultaneously. Immediately archiving all backup data (C) does not address geography and, if the archive remains on-site, offers no protection against fire or flood either. Backing up to another storage system in the same location (D) improves protection against device-level failure but does nothing against a site-wide event that would damage all on-site equipment together. Keeping backups only locally (E) is the opposite of what the scenario requires. Remote or cloud storage is correct.

Reference topic: Data Backup and Deduplication - Offsite and Cloud Backup for Disaster Protection.