The software architecture of a program or
题型：单项选择题
问题：
The software architecture of a program or computing system is the structure or structures of the system, which comprise software ______, the externally ______properties of those components, and the relationships between them.The architecture is not the operational software. Rather, it is a ______ that enables a software engineer to: analyze the ______ of the design in meeting its stated requirements, consider architectural alternatives at a stage when making design changes is still relatively easy, and reduce the ______ associated with the construction of the software.
A. changeability B. effectiveness C. testability D. functionality