You are designing a new backup solution for Certkiller .com. After an initial analysis, you decide to implement a two tier solution. The first tier is disk and the second is tape. A retention period needs to be defined for the first tier which will determine when backup data will be moved to the second tier. What determines this retention period?

A.
Recovery point objective

B.
Available bandwidth

C.
Backup type

D.
Percentage of restore requests over time