Which testing phase validates business user requirements and usability?

• A. Unit testing
• B. User Acceptance Testing (UAT)
• C. SIT
• D. Regression testing

Answer: (B)

The thing being tested is whether the system meets business user needs and can be used effectively in real work, as verified by the end users themselves. In this phase, business representatives run typical end-to-end scenarios, review data flows and reporting, and judge whether the solution supports day-to-day processes. Usability is considered because the users must be able to perform tasks smoothly and efficiently, leading to formal acceptance and readiness for production.

This differs from testing focused on technical parts or integration: unit testing checks individual components, system integration testing examines how modules work together, and regression testing ensures existing features still function after changes. The aim of this phase is the business's acceptance, confirming the solution satisfies requirements and is usable in practice.