The scenario describes an incremental development model (sprints) where new and amended interfaces are delivered progressively. The most effective Test Automation Solution (TAS) in this context must support early and continuous testing. Option C provides a robust, multi-layered approach. By creating customized hooks (stubs and drivers) at the component level, individual interfaces can be tested in isolation as soon as they are developed, without waiting for dependent interfaces. This facilitates early feedback within each sprint. As components are completed, they are integrated and tested at the system level using the actual interfaces. This dual-level strategy ensures both the correctness of individual components and the integrity of their integration, aligning perfectly with Agile and incremental principles.

A. This "big-bang" automation approach is inefficient and contradicts the incremental delivery model by delaying all automation and feedback until the end.

B. Ignoring component-level testing and refusing to use test hooks makes it impossible to test interfaces in isolation, preventing early defect detection in a sprint-based project.

D. This approach is incomplete. While component-level testing with hooks is valuable, omitting system-level testing fails to verify that the interfaces integrate and function correctly together.

1. ISTQB® Certified Tester Advanced Level Test Automation Engineer Syllabus V1.0 (2016):

Section 2.3.1, The TAS Architecture: This section discusses the need for a layered architecture, including a "Test Adaptation Layer" which contains the necessary drivers and stubs (i.e., customized hooks) to interact with the SUT at different interface levels. This supports testing components in isolation.

Section 4.1.1, Selecting the Test Automation Approach: This section emphasizes that the chosen approach must align with the System Development Lifecycle (SDLC). For an incremental model, "the TAS must be able to test increments of the SUT as they are developed," which necessitates the use of stubs for undeveloped components, as described in option C.

Section 2.3.2, Designing the TAS: It states the TAS design must consider the "levels of testing to be automated (e.g., component, integration, system)." The scenario requires testing interfaces, which involves both component and integration (system) level verification. Option C is the only one that correctly addresses both levels in an incremental context.