The organization should define what constitutes a policy violation. A policy violation refers to the breach or violation of a written policy or rule of the organization. A policy or rule is a statement that defines the expectations, standards, or requirements for the behavior, conduct, or performance of the organization's members, such as employees, customers, partners, or suppliers. Policies and rules can be based on various sources, such as laws, regulations, contracts, agreements, principles, values, ethics, or best practices12.
The organization should define what constitutes a policy violation because it is responsible for establishing, communicating, enforcing, and monitoring its own policies and rules. The organization should also define the consequences and remedies for policy violations, such as warnings, sanctions, penalties, termination, or legal action. The organization should ensure that its policies and rules are clear, consistent, fair, and aligned with its mission, vision, and goals12.
The other options are not correct. Option A, the external auditor, is incorrect because the external auditor is an independent party that provides assurance or verification of the organization's financial statements, internal controls, compliance status, or performance. The external auditor does not define the organization's policies and rules, but evaluates them against relevant standards or criteria3. Option C, the Internet service provider (ISP), is incorrect because the ISP is a company that provides access to the Internet and related services to the organization. The ISP does not define the organization's policies and rules, but may have its own policies and rules that the organization has to comply with as a customer4. Option D, the cloud provider, is incorrect because the cloud provider is a company that provides cloud computing services to the organization. The cloud provider does not define the organization's policies and rules, but may have its own policies and rules that the organization has to comply with as a customer5. References :=
* Policy Violation Definition | Law Insider1
* How to Write Policies and Procedures | Smartsheet2
* What is an External Auditor? - Definition from Safeopedia3
* What is an Internet Service Provider (ISP)? - Definition from Techopedia4
* What is Cloud Provider? - Definition from Techopedia

ISO/IEC 15027017 is a cloud-specific security standard that provides guidelines for information security controls applicable to the provision and use of cloud services. It is based on ISO/IEC 27002, which is a general standard for information security management, but it also includes additional controls and implementation guidance that specifically relate to cloud services. ISO/IEC 15027017 is intended to help both cloud service providers and cloud service customers to enhance the security and confidentiality of their cloud environment and to comply with relevant regulatory requirements and industry standards.12 References := ISO/IEC
27017:2015 - Information technology - Security techniques - Code of practice for information security controls based on ISO/IEC 27002 for cloud services1; Cloud Security Standards: ISO, PCI, GDPR and Your Cloud - Exabeam3; ISO/IEC 27017 - Wikipedia2

The greatest concern to the auditor should be that the customer cannot monitor its cloud subscription on its own and must rely on the provider for monitoring purposes. This situation can lead to a lack of transparency and control over the security and compliance posture of the cloud services being used. It is crucial for customers to have the ability to independently monitor their systems to ensure that they are secure and compliant with relevant regulations and standards.
References = This concern is highlighted in the Cloud Security Alliance's (CSA) Cloud Controls Matrix (CCM) and the Certificate of Cloud Auditing Knowledge (CCAK) materials, which emphasize the importance of continuous monitoring and the customer's ability to audit and ensure the security of their cloud services1.

Access controls are an assurance requirement when an organization is migrating to a SaaS provider because they ensure that only authorized users can access the cloud services and data. Access controls also help to protect the confidentiality, integrity and availability of the cloud resources. Access controls are part of the Cloud Control Matrix (CCM) domain IAM-01: Identity and Access Management Policy and Procedures, which states that "The organization should have a policy and procedures to manage user identities and access to cloud services and data."1 Reference := CCAK Study Guide, Chapter 4: A Threat Analysis Methodology for Cloud Using CCM, page 751