A DMZ (Demilitarized Zone) typically contains:

A.
A customer account database

B.
Staff workstations

C.
A FTP (File Transfer Protocol) server

D.
A SQL (Structured Query Language) based database server

Explanation:
A DMZ is an area where you can place a public server for access by people you might not trust otherwise. By isolating a server in a DMZ, you can hide or remove access to other areas of your network. A FTP server is can be used my people from outside of your network and should be placed in the DMZ.
Reference: Security + (SYBEX) page 26