Accelerated analysis approaches emphasize

问题：

Accelerated analysis approaches emphasize the construction of （） to more rapidly identify business and user requirements for a new system. As an accelerated analysis technology,（） reads the program code and automatically generates the equivalent system model, and the code can be obtained from （） . All system analysis approaches require some form of （） which includes those techniques to be used to identify or extract system problems and solution requirements from user community. （） is a classical set of techniques used to collect information about system problems, opportunities, solution requirements, and priorities.

and the code can be obtained from （）

A．existing database and application program

B．application program and user interface

C．existing database and user interface

D．existing database, application program and user interface