In an ISD (Interface Structure Design),a Common Approach Is to Draw

In an ISD (Interface Structure Design) ,a common approach is to draw numbered boxes in a tree-type structure.This structure indicates ________

A) A strict hierarchy of parent / child processes (as shown on Level 0 / Level 1 and Level 2 DFDs)
B) An adherence to the use cases with all possible paths
C) A relationship between menus and submenus
D) A structural functionality as established on the use scenario
E) Commonly occurring use cases