Choice "D" is correct. Storing duplicate copies of key files in a separate location can help a company continue operations in the event a disaster destroys the originals.
Choice "a" is incorrect. Conversion of data from EDI format to internal company format (using translation software) is necessary for companies that wish to utilize EDI, but it does not aid in disaster recovery.
Choice "b" is incorrect. Trojan horse programs perform rather than prevent illicit activity.
Choice "c" is incorrect. Provision of uninterrupted electricity may prevent accidental loss of data, but it does not help a company recover from a disaster that has already occurred.