Rapid Application Development (RAD) is an agile software development methodology that emphasizes speed and adaptability. Its core characteristic is the use of iterative development and the creation of prototypes. Unlike traditional models, RAD involves users actively and continuously throughout the development cycle. Prototypes are built, presented to users for feedback, and then refined in rapid succession. This iterative feedback loop ensures the final product aligns closely with user requirements and can be delivered much faster than with linear approaches.

B. This describes the Waterfall model, where comprehensive planning and documentation are completed before any coding begins, which is contrary to RAD's flexible approach.

C. This is the defining characteristic of the Waterfall model, which follows a strict, sequential path from requirements to deployment without iteration.

D. This is the opposite of the RAD model's philosophy, which mandates high levels of user interaction and feedback to guide the iterative prototyping process.

1. Pressman, R. S., & Maxim, B. R. (2020). Software Engineering: A Practitioner's Approach (9th ed.). McGraw-Hill. In Chapter 4, "Prescriptive Process Models," the RAD model is described as an incremental process that emphasizes a short development cycle, with a key phase being "modeling" which involves creating prototypes for user evaluation (pp. 70-71).

2. Martin, J. (1991). Rapid Application Development. Macmillan Publishing Co. The foundational text for RAD defines the methodology around four essential elements: tools, people, methodology, and management. The methodology pillar is built on iterative prototyping and heavy user involvement, referred to as Joint Application Design (JAD) sessions (Part II, Chapters 5-7).

3. Stellman, A., & Greene, J. (2014). Learning Agile: Understanding Scrum, XP, Lean, and Kanban. O'Reilly Media. Chapter 2, "Understanding Agile Values," contrasts agile methods like RAD with plan-driven approaches, highlighting that RAD relies on "iterative development and frequent user feedback" to manage changing requirements.

4. University of Virginia, Department of Computer Science. (n.d.). CS 4720: Software Engineering, Lecture 5: Process Models. The course materials describe RAD as a model that "relies on extensive user involvement" and uses "prototyping and iterative development" to construct systems.