A company purchases a new file server rated at 3U. The new server needs to be installed in the server rack, where other file servers are installed. Rack space is limited and it must be determined whether or not the rack will accommodate the new server. How much vertical space does the new server need?

A.
4.25 in (10.8 cm)

B.
5.25 in (13.3 cm)

C.
3.25 in (8.3 cm)

D.
2.25 in (5.7 cm)