单项选择题
An architectural Style defines as a family of such systems in terms of a （） 、of structural organization.More specifically an architectural style defines a vocabulary of（） and connector types, and a set of （） on how they can be combined. For many styles there may also exist one or more （） 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 （） architectures are programs written in the Unix shell．
An architectural Style defines as a family of such systems in terms of a （）、of structural organization.
A．pattern
B．data flow
C．business process
D．position level