（）analysis emphasizes the drawing of pictorial system models to document and validate both existing and/or proposed systems. Ultimately, the system models become the（）for designing and constructing an improved system.（）is such a technique. The emphasis in this technique is process-centereD. Systems analysts draw a series of process models called（）.（）is another such technique that integrates data and process concerns into constructs called objects.
Systems analysts draw a series of process models called （）.
A．PERT
B．DFD
C．ERD
D．UML