1. True. In a unit test, a individual component is tested in isolation. In an object-oriented language, this is often a single class.
2. False. In an integration test, the correct working of a group of components is verified, and not the entire assembled system. If the entire assembled and deployed system is tested, this is referred to as a system test.
3. Answer number 2 is correct. The testing pyramid prescribes a large set of unit tests that verify as many requirements as possible. Integration tests are added only for those risks that cannot be covered using unit tests, resulting in a lower number of integration tests. Even fewer system tests are added, only to cover the risks not covered by either unit or integration tests.
4. Answer number 3 is correct. All other types of testing are covered in this chapter.
5. Two techniques that can be mentioned here are code reviews and pipeline gates. Code reviews allow developers to review the work of their colleagues to help each other keep quality high. Pipeline gates can be used to not allow a build or version of an application to propagate further down a pipeline if certain conditions are not met. Example conditions can include certain quality metrics, or minimum standards for test coverage or test results.