What is a common issue faced in Test-First Development?

Test-First Development, also known as Test-Driven Development (TDD), focuses on writing tests before writing the actual code that fulfills those tests. One of the common challenges encountered in this methodology is related to complex user interfaces (UI).

When developing applications with intricate UIs, creating incremental tests can be quite challenging. This complexity arises from the need to accurately simulate user interactions and verify that the various components work as intended together over time. Testing incremental changes in such a complex system can lead to difficulties in ensuring coverage and maintaining test clarity. The dynamic nature of UI elements, changes in state, and the potential for various user paths further complicate the testing process. As the UI evolves, keeping tests relevant and manageable without becoming overly rigid or fragile can be a significant hurdle.

This challenge is specific to the nature of user interface development, where changes often affect multiple components and may require a re-evaluation of existing tests. Thus, option C accurately captures a common issue in Test-First Development.