DSS components and control points: In a Decision Support System, which of the following are not major subsystems that provide opportunities for system design controls?

Introduction / Context:
Classic DSS architecture includes three pillars: the database (data management subsystem), the model base (model management subsystem), and the dialog or language subsystem (user interface). Effective control and governance mechanisms can be embedded in each pillar. This question asks which listed subsystems are not major control points.

Given Data / Assumptions:

• Database controls include data quality, lineage, access rights, and backup.
• Model base controls include versioning, validation, documentation, and audit trails.
• All pillars provide opportunities for design controls.

Concept / Approach:
Because both the database and model base are core DSS subsystems, each is a rich locus for controls. Data integrity and security are enforced in the database; correctness and transparency are enforced in the model base. Therefore, it is incorrect to say either one is “not” a major subsystem for controls. The correct response is that neither is excluded—they both are major control points.

Step-by-Step Solution:

Verification / Alternative check:
DSS texts and frameworks (data, model, dialog) treat all layers as control targets—security, quality, and governance span the stack.

Why Other Options Are Wrong:

• Database or model base individually: both are major and deserve controls.
• Both (a) and (b): would imply neither is major, which is false.
• None of the above: not precise, since option D already captures the correct logic.

Common Pitfalls:
Under-controlling models; governance should cover data and analytical models due to decision impact.

Final Answer:
neither (a) nor (b)