Deleting subscription owner accounts is an activity that MUST obtain a client's approval in the context of cloud service provider activities. Subscription owner accounts are critical as they hold the ownership and control over the resources and services within a cloud subscription. Deleting these accounts can have significant implications, including loss of access, control, and potential data loss. Therefore, it is essential for a cloud service provider to seek explicit approval from the client before proceeding with such an action to ensure transparency, maintain trust, and avoid any unintended consequences.
Reference:
Microsoft Trust Center, Cloud Services Due Diligence Checklist1.
Google Cloud, What is a Cloud Service Provider?2.
Partner Center, CSP agreements, price lists, and offers3.
Microsoft Azure, How to choose a cloud service provider4.
FCA, FG16/5 Guidance for firms outsourcing to the 'cloud' and other third-party IT services

Establishing ownership and accountability most enhances the internal stakeholder decision-making process for the remediation of risks identified from an organization's cloud compliance program. Cloud compliance refers to the principle that cloud-delivered systems must comply with the standards required by their customers. Compliance requirements may include data protection regulations such as HIPAA, PCI DSS, GDPR, ISO/IEC 27001, NIST, and SOX. A cloud compliance program is a set of policies, procedures, and controls that help an organization to achieve and maintain compliance with these requirements12.
A cloud compliance program involves identifying, assessing, prioritizing, and mitigating the risks associated with using cloud services. To effectively manage these risks, an organization needs to establish ownership and accountability for each risk and its remediation. Ownership and accountability mean assigning clear roles and responsibilities to the internal stakeholders who are involved in the cloud compliance program, such as the cloud service provider, the cloud customer, the cloud users, the cloud auditors, and the cloud regulators. By doing so, an organization can ensure that the internal stakeholders have the authority, resources, and incentives to make timely and informed decisions for the remediation of risks123.
The other options are not the most effective ways to enhance the internal stakeholder decision-making process for the remediation of risks. Option A, automating risk monitoring and reporting processes, is a good practice for improving the efficiency and accuracy of the cloud compliance program, but it does not address the issue of who is responsible for making decisions based on the monitoring and reporting results. Option B, reporting emerging threats to senior stakeholders, is a good practice for increasing the awareness and visibility of the cloud compliance program, but it does not address the issue of how to prioritize and respond to the emerging threats. Option D, monitoring key risk indicators (KRIs) for multi-cloud environments, is a good practice for measuring and tracking the performance and effectiveness of the cloud compliance program, but it does not address the issue of how to align and coordinate the decisions across different cloud environments123. Reference := Cloud Compliance Frameworks: What You Need to Know1 Cloud Compliance: What It Is + 8 Best Practices for Improving It2 Cloud Computing: Auditing Challenges - ISACA

Explanation
Regarding cloud service provider agreements and contracts, unless otherwise stated, the provider is responsible only to the cloud customer. This means that the provider has a contractual obligation to deliver the agreed-upon services and meet the service level agreements (SLAs) with the cloud customer, who is the direct payer of the services. The provider is not responsible for any other parties, such as the cloud customer's clients, end users, or regulators, unless explicitly specified in the contract. The cloud customer is responsible for ensuring that the provider's services meet their own compliance and security requirements, as well as those of their stakeholders12.
References:
Shared responsibility in the cloud - Microsoft Azure
Cloud security shared responsibility model - NCSC

This situation poses a significant concern for a cloud auditor because it indicates a potential gap in the technical team's ability to effectively manage and secure the IaaS platform provided by the alternative vendor. Without proper training on the specific features, security practices, and operational procedures of the new platform, the organization may face increased risks of misconfiguration, security vulnerabilities, and inefficiencies in cloud operations. It is crucial for the technical team to have a comprehensive understanding of all platforms in use to ensure they can maintain the security and performance standards required for a robust cloud environment.
Reference = The concern is based on common cloud auditing challenges, such as controlling and monitoring user access, and ensuring the IT team is equipped to manage the cloud environment effectively12. Additionally, best practices suggest that network segmentation, user authentication, and access control are critical areas to address in a cloud audit3. These principles are widely recognized in the field of cloud security and compliance.