Final answer:
The test method that guarantees the proper functioning of the application system by evaluating every possible path and condition is called exhaustive testing. However, exhaustive testing is generally impractical for complex applications due to the enormous number of combinations it entails.
Step-by-step explanation:
The only test method that guarantees the proper functioning of the application system by evaluating every possible path and condition is called exhaustive testing. Exhaustive testing is an impractical level of testing where every possible combination of inputs and preconditions are tested. It's generally impossible for non-trivial applications due to the sheer number of possible combinations, but theoretically, it would ensure the most thorough testing of an application.
Different from regression testing, basic path testing, and branch testing, exhaustive testing requires significantly more resources and time and is typically not feasible. Regression testing involves retesting to confirm that recent code changes have not adversely affected existing features, basic path testing involves testing paths through the program to ensure that all statements have been executed at least once, and branch testing ensures that each possible branch from a decision point is executed.
Therefore, the correct answer is B. Exhaustive Testing.