Detailed Answer
(d) The requirement is to determine why the grandfather-
father-son updating backup concept is relatively difficult to
implement for disk files. Answer (d) is correct because updating
destroys the old records. Answer (a) is incorrect because the
location of information points on disks is not an extremely time
consuming task if the disks have been properly organized and
maintained. Answer (b) is incorrect because off-site storage
through disks is possible, though costly. Answer (c) is incorrect
because information need not be dumped in the form of hard
copy.