To answer this question, you need to understand the different types of testing.
Option A) Unit Testing - This option is incorrect because unit testing involves testing individual components or modules of a software system in isolation, not by going through the code.
Option B) Blackbox Testing - This option is incorrect because blackbox testing focuses on testing the functionality of a software system without any knowledge of its internal workings or code.
Option C) White Box Testing - This option is correct because white box testing, also known as code-based testing or structural testing, involves testing the internal structure or code of a software system to ensure that it functions correctly.
Option D) Regression Testing - This option is incorrect because regression testing is a type of testing that is performed to ensure that previously developed and tested software still works after any changes or modifications have been made.
The correct answer is C) White Box Testing. This option is correct because it refers to the testing that is done by going through the code or internal structure of the software system.