Final answer:
Debugging in software development specifically refers to the process where a developer identifies and corrects defects in the code. Hence, among the provided options, 'A developer finds and fixes a defect' is an example of debugging.
Step-by-step explanation:
The question relates to the process of debugging, which is an aspect of software development. Debugging involves identifying, isolating, and fixing bugs or defects in a program's code. When reviewing the provided options, we can determine that option C, "A developer finds and fixes a defect", directly corresponds to the definition of debugging. This is because debugging encapsulates the entire process of dealing with a bug: finding it, understanding it, and correcting it. The other options, such as reporting a defect or conducting unit testing, are related to the broader software testing process but are not specifically the act of debugging itself.