The Open Source Security Testing Methodology Manual emphasizes the importance of educational property and integrity in the process of security testing. It is not just about finding vulnerabilities but also about ensuring that the learning from the process improves the overall security posture of the organization. By following a disciplined methodology, the incident response team verifies the comprehensiveness of testing while maintaining the integrity and confidentiality of the system being tested. Answer 'C' is correct because, according to OSS TMM, one should conduct tests without disrupting the organization's operational activities whenever possible. This approach prioritizes maintaining business continuity and minimizing impact during incident response activities, aligning with the concepts of OSS TMM.