A Web hosting facility has five new clients. Clients often visit the server room to oversee server operations. Which of the following is the MOST cost-effective, yet physically secure arrangement for this situation?

A.
Clients should be given keys to the server room and asked to sign in.

B.
Servers should be installed in separate locked server rooms.

C.
The server room should be video monitored for security purposes.

D.
Servers should be installed in separate locked server racks within one server room.