An architectural Style. defines as a family of such systems in terms of a (1) of structural organization.More specifically an architectural style. defines a vocabulary of (2) and connector types, and a set of (3) on how they can be combined. For many styles there may also exist one or more (4) that specify how to determine a system's overall properties from the properties of its parts. Many of architectural styles have been developed over the years.The best-known examples of (5) architectures are programs written in the Unix shell．
(1)

A. pattern
B. data flow
C. business process
D. position level