Asystem's architecture is a representation of a system in which there is amapping of（71）onto hardware and softwarecomponents, a mapping of the（72）onto thehardware architecture. and a concern for the human interaction with thesecomponents. That is, system architecture is concerned with a total system, includinghardware. software, and humans.
Softwarearchitectural structures can be divided into three major categories, dependingon the broad nature of the elements they show.1）（73）embodydecisions as a set of code or data units that have to be constructed orprocured.2）（74）embody decisions as to how the systemis to be structured as set of elements that have runtime behavior. andinteractions.3）（75）embody decisions as to how thesystem will relate to nonsoftware structures in its
environment(suchas CPUs, file systems, networks, development teams, etc.).
71.()

A. attributes
B. constraint
C. functionality
D. requirements