Which of the following are the typical defects found by static analysis tools?

Static analysis tools are designed to analyze code without executing it, allowing them to identify various types of defects early in the software development lifecycle. Among the typical defects identified, unreachable code stands out as a significant example.

Unreachable code is any section of code that cannot be executed under any circumstances, which may result from logical errors, redundant conditions, or incorrect control flow. Static analysis tools can flag such code as a defect because it indicates a potential oversight in the coding process. Detecting unreachable code is essential, as it can lead to confusion for developers maintaining the code and may harbor hidden bugs if future modifications are made.

On the other hand, while other options like unused variables, security vulnerabilities, and performance issues can also be examined by static analysis tools, they may not be as universally detected as unreachable code. Unreachable code is a clear-cut issue that static analysis can easily pinpoint, highlighting its unique relevance in the context of the typical defects that these tools are most effective at finding.