How does a Cisco CallManager know that there are audio source files to be translated for music-on-hold?

A.
A check box is selected in the Cisco CallManager admin pages each time there is a file to be processed.

B.
Files are dropped into a directory maintained and checked automatically by Cisco CallManager.

C.
A special application is run by the administrator whenever files are added.

D.
The administrator uses TFTP to transfer the files to a special server.