The model in which the requirements are implemented by its category is

Answer: Evolutionary Development Model

Why this is correct: Evolutionary Development builds the system through successive versions, with each version implementing a subset of requirements. These subsets are often grouped by functional category or priority, so requirements are implemented by category and refined in later versions.

• Waterfall Model: A linear, phase-driven approach where requirements are gathered and implemented in sequence; it does not deliver requirement categories across evolving releases.

• Prototyping Model: Focuses on building prototypes to clarify and validate requirements rather than implementing groups of requirements across staged versions.

• Iterative Enhancement Model: Delivers repeated enhancements and can add functionality incrementally, but it usually emphasizes incremental improvement rather than explicitly implementing predefined requirement categories in staged releases.