Final answer:
Option D) is NOT an advantage of incremental development and delivery models. While earlier increments are well tested, it is not guaranteed that the most critical system services will receive the most testing, which is essential for ensuring product quality.
Step-by-step explanation:
The question pertains to the evaluation of the major advantages of incremental development and delivery models. Incremental development refers to the process where the design is done in pieces, and aspects of the design can be prototyped, tested, and refined through multiple iterations. Each phase yields a workable version of the software, which is then built upon in subsequent phases, providing multiple opportunities for evaluation and refinement.
Option A) describes one of the primary benefits of this approach, as early increments can indeed serve as a form of prototype to gather requirements for later increments, offering practical feedback.
Option B) is another advantage, which makes the model particularly effective for replacement development because earlier stages can verify the approach's validity, thereby reducing the risk of project failure.
Option C) highlights that with incremental development, a portion of the system is usable long before the entire system is completed, thereby getting the product to market sooner.
However, Option D) is not necessarily correct; although earlier increments do tend to be more thoroughly tested, it does not imply that later increments, or the most critical system services, receive the most testing by default. In fact, issues can occur if the most crucial features are developed in later stages but are not as rigorously tested as the earlier ones.