The traditional model for systems development was that an IT department used （1） which is a process-centered technique, and consulted users only when their input or approval was needed. Compared with traditional methods, many companies find that JAD allows （2） to participate effectively in the requirements modeling process. When properly used, JAD can result in a more accurate statement of system requirements, a beret understanding of common goals, and a per commitment to the success of the new system. RAD is a （3） technique that speeds up information systems development and produces a functioning information system. While the end product of JAD is a(an) （4）, the end product of RAD is the new information system. The RAD model consists of tour phases. During the （5）, users interact with systems analysts and develop models and prototypes that represent all system processes, outputs, and inputs.
（2）处填（）。
A．project managers
B．system administrators
C．software programmers
D．key users
