Which of the following best defines 'test execution'?

The correct answer defines 'test execution' as the phase in which test cases are run to verify that the software functions as intended. This is a critical step in the software testing process, as it allows for the actual evaluation of the application's performance against the predefined requirements and expectations. During this phase, testers actively engage with the application, applying their test cases and observing the outcomes. This process helps identify defects or areas of improvement in the software, providing vital feedback to the development team.

In contrast, the other options describe related but distinct activities within the overall testing process. Documenting test results refers to the recording of the outcomes after the tests have been executed, which happens post-execution. Preparing tests for execution pertains to the planning and setup required before any actual testing takes place, ensuring that everything needed is in place to facilitate effective testing. Lastly, the final review of test documentation occurs after the tests are executed and results are documented, primarily focusing on ensuring everything is complete and accurate before concluding the testing phase. Each of these activities is essential to the overall testing strategy but does not encapsulate the act of executing the tests themselves.