The correct answer is 'Executive summary.' An executive summary is essential in a penetration testing report as it provides an overview of the most significant findings and risks without the technical details. It is tailored for recipients such as C-suite executives who need to quickly understand the potential impact on the business to make decisions, hence it is concise and avoids technical jargon. While 'Scope details,' 'Methodology,' and 'Findings' are critical components of the report, they are usually more technical and detailed, aimed at individuals who are actively engaged in the remediation process or require a deep understanding of the procedure and results.