To ensure that critical company data can easily be restored and operations can continue; which of the following is necessary? Choose all that apply.

A.
Store a copy of each backup onsite and offsite.

B.
Store copies of critical applications offsite.

C.
Have a spare tape drive and cable on hand.

D.
All of the above.

Explanation:
You should make two sets of each backup and store one copy onsite so that it can easily be accessed. The other copy should be stored offsite so that you can use it to recover from natural disasters, such as floods and hurricanes. You should also store copies of critical applications offsite. You should have a spare tape drive and cable on hand as well.
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 549-551.