Which of the following is NOT a metric of code quality?

Lines of Code is not a direct metric of code quality. While it can offer insights into the size of a codebase and may be used in various analyses, it does not inherently reflect the quality of the code itself. High lines of code could mean a complex project, potentially leading to more quality issues, whereas less code could be poorly written or not functional at all. Quality metrics typically focus on attributes like maintainability, reliability, performance, and correctness, which are better represented by other options given.

On the other hand, code reviews serve as a qualitative measure of code quality as they evaluate adherence to standards, design principles, and common coding practices. Bug counts are a direct indicator of issues found in the code, showing how many defects exist and thus impacting quality. Cycle time per feature, which measures the time it takes to develop and deliver a feature, can also signal code quality indirectly; longer cycles can indicate underlying quality issues that slow down development.

Therefore, while lines of code is an interesting metric related to development activity, it does not provide a meaningful measure of the actual quality of the code produced.