What method is used to track the execution of a program to identify performance issues?

Tracing is a method used to monitor the execution of a program to gather data about its performance and behavior. This technique involves logging specific events, function calls, or state changes to provide insights into how a program operates over time. By collecting this detailed information, developers and system administrators can pinpoint performance bottlenecks, identify areas of inefficient resource use, and trace the flow of execution through the code. The visibility gained from tracing allows for better diagnosis of performance issues, ultimately leading to more effective optimization and debugging strategies.

In contrast, functionality testing focuses on verifying that a program operates according to specified requirements, rather than monitoring its execution for performance issues. Incident response is concerned with how an organization reacts to security incidents or breaches, which is unrelated to performance tracking. Performance tuning refers to the process of optimizing a system's performance based on findings from methods like tracing, but it is not a method of tracking itself. Therefore, tracing stands out as the appropriate technique specifically aimed at tracking program execution to identify performance issues.