Information systems design is defined as those tasks that focus on the specification of a detailed computer-based solution. Typically, there are four systems design tasks for in-house development.
①The first task is to specify （1）, which defines the technologies to be used by one, more, or all information systems in terms of their data, processes, interfaces, and network components. This task is accomplished by analyzing the data models and process models that are initially created during requirements analysis.
②The next systems design task is to develop the （2）. The purpose of this task is to prepare technical design specifications for a database that will be adaptable to future requirements and expansion.
③Once the database prototype has been built, the systems designer can work closely with system users to develop input, output and dialogue specifications. The （3）ust be specified to ensure that the outputs are not lost, misrouted, misused, or incomplete.
④The fourth design task involves packaging all the specifications from the previous design tasks into a set of specifications that will guide the （4） activities during the following phases of the systems development methodology.
Finally, we should （5） and update the project plan accordingly. The key deliverable should include a detailed plan for the construction phase that should follow.
（1）是（）
A. an application architecture
B. a distributed system
C. a system scope
D. a system physical model
