Confirmation testing, also known as re-testing, is performed to verify that specific defects have been successfully fixed.
Option A: "Testing due to the application of a new version of the interface" would typically involve regression testing, not confirmation testing.
Option B: "Testing that fixes resolved the defects in the search function" fits the description of confirmation testing as it focuses on ensuring that specific issues have been addressed.
Option C: "Testing if a system still works after update of an operating system" is an example of regression testing, as it checks the overall system behavior after an update.
Option D: "Testing to ensure the adding of new functionalities haven't broken existing functions" is another example of re(ISTQB not-for-profit association)(Udemy) it checks for unintended consequences of new changes.
Therefore, the correct answer isB#6†source##9†source#.
References:
* Certified Tester Foundation Level v4.0
* ISTQB Foundation Level Syllabus 4.0 (2023)