Final answer:
Vulnerability scan reports should be kept organized and accessible for future reference, tracking progress, and compliance validation.
Step-by-step explanation:
The correct answer to what you should do with your growing library of vulnerability scan reports is, (b) Keep them organized and accessible for future reference and analysis. The vulnerability scan reports hold vital information about the security weaknesses in your system. They can be crucial for tracking progress over time, identifying patterns or recurrent issues, and validating compliance with security standards. Therefore, it is essential to keep these reports well-organized so that you can refer to them when planning security improvements or during security audits.