Rapid prototyping helps prove the quality and suitability of a design by both simulating the real system and presenting the design to users and stakeholders for feedback.

Introduction / Context:
Rapid prototyping emphasizes quickly building working models (or interactive mockups) to validate requirements, usability, and technical feasibility. Prototypes reveal misunderstandings early and enable iterative refinement, improving design quality before costly full-scale development.

Given Data / Assumptions:

• A prototype can simulate essential system behavior.
• Stakeholder walkthroughs and presentations gather feedback and align expectations.
• Artifacts like DFDs may support understanding but are not sufficient alone.

Concept / Approach:
Two complementary tactics “prove” a design: (1) executable or interactive simulations that users can try with realistic scenarios; and (2) structured reviews where analysts present rationale, flows, and trade-offs to users, developers, and advisors for critique. Together, these reduce ambiguity and surface usability or scope issues early.

Step-by-Step Solution:
Create a minimal but functional prototype covering key workflows.Run simulations or usability sessions to observe behavior and collect feedback.Conduct review meetings where the analyst presents the design, assumptions, and evidence from prototype sessions.Iterate on the prototype until acceptance criteria are satisfied.

Verification / Alternative check:
Projects that employ rapid prototypes usually report reduced rework during implementation because requirements have been validated interactively and socially (via presentations), supporting the dual nature of option D.

Why Other Options Are Wrong:
Option A alone omits essential stakeholder alignment. Option B alone lacks hands-on validation of behavior. Option C (DFDs) describes data movement models, helpful but insufficient to prove design quality by themselves. Option E is wrong because both A and B together are correct.

Common Pitfalls:
Mistaking high-fidelity visuals for validated designs; neglecting edge cases; skipping real user sessions. Prototyping must be iterative and evidence-driven to be effective.

Final Answer:
both (a) and (b)