Which SDLC model emphasizes prototyping as part of the cyclical process?

• A. Waterfall
• B. Iterative
• C. Spiral
• D. All of the above

Answer: (C)

Prototyping is most central in the Spiral model because each loop of the development cycle explicitly uses a prototype to explore requirements and reduce risk before moving forward. The process is repeated in cycles (spirals), with activities that include defining objectives and constraints, assessing and mitigating risks, building and validating a prototype, and planning the next increment. This risk-driven, prototype-focused approach repeats until the system is fully delivered. Waterfall follows a linear sequence with limited opportunity to prototype within phases, and a generic Iterative approach repeats development but doesn’t inherently make prototyping in every cycle its defining feature. The deliberate, cycle-by-cycle use of prototypes to confirm needs and manage risk is what makes the Spiral model the best fit.