The service that best meets this need is one that offers on-demand access to compliance documentation and agreements. It provides resources such as Service Organization Control (SOC) reports, PCI DSS certifications, and other documentation that validate the conformity of cloud services to a wide array of regulatory requirements, thereby aiding in data protection and retention compliance efforts. Other services mentioned, like the ones that focus on security monitoring and threat detection, are essential for the ongoing protection and assessment of cloud infrastructure but do not serve the primary purpose of providing compliance documentation.