To solve this question, the user needs to know about different types of testing used in software development. The user needs to identify which type of testing fits the given description.

The given description matches with the concept of Unit Testing. Unit testing is a software testing technique in which individual units or components of a software application are tested in isolation from the rest of the application. It is the process of testing individual units of source code to determine whether they are fit for use.

Now, let's go through each option and explain why it is right or wrong:

A. Integration testing: Integration testing is a software testing technique that tests the interaction between software modules. It is performed after unit testing and before system testing. This option is incorrect because the given description is not talking about integration testing.

B. System testing: System testing is a software testing technique in which a complete and integrated software system is tested. It is performed after integration testing and before user acceptance testing. This option is incorrect because the given description doesn't match the concept of system testing.

C. Unit testing: This option is correct. The given description matches the concept of unit testing. Unit testing is the process of testing individual units or components of a software application for proper operation.

D. Static testing: Static testing is a software testing technique in which the code is tested without executing it. It is performed by analyzing the code or documentation. This option is incorrect because static testing doesn't involve testing the smallest testable parts of an application individually and independently.

The Answer is: C