Which of the following statements about white-box testing is false?

The statement "Achieving full code coverage for a component or a system ensures that it has been fully tested" is false because achieving full code coverage does not necessarily mean that all possible defects have been identified or that the system is free of bugs. Code coverage metrics, such as statement coverage, branch coverage, or path coverage, only measure the extent to which the source code has been executed during testing, but they do not guarantee that all logical paths or use cases have been exercised or that the code behaves correctly under all conditions.

Full code coverage indicates that every line of code has been executed at least once, but it does not account for the quality of the test cases or their ability to detect defects. There can still be issues related to performance, usability, security, and other non-functional aspects that are not addressed by code coverage alone.