posted by fred .
In an online, real-time system, which of the following would be most likely to be used as backup for an application's master file maintained on magnetic disk?
A) At specified periods the disk files would be dumped to (copied on) magnetic tape along with the period's transactions
B) A duplicate disk file would be maintained and all activity would be copied on magnetic tape continuously
C) The grandfather-parent-child technique would be employed to retain disk files
D) All source documents for transactions would be retained
E) The disk files would be copied to magnetic tape continuously