Using a standardized control framework enables auditors to conduct gap analyses of what a cloud service provider (CSP) offers versus what the customer requires. A standardized control framework is a set of guidelines, best practices, and criteria that help to evaluate and improve the security, privacy, and compliance of cloud computing environments. Examples of standardized control frameworks include ISO/IEC 27001/27002/27017/27018, NIST SP 800-53, CSA Cloud Controls Matrix (CCM), COBIT, etc. By using a standardized control framework, auditors can compare the CSP's policies, procedures, and practices with the customer's expectations and requirements, and identify any gaps or discrepancies that may pose risks or issues. A gap analysis can help the auditors to provide recommendations and suggestions to the CSP and the customer on how to close the gaps and enhance the quality and performance of the cloud services12.
Reference:
Cloud Controls Matrix (CCM) - CSA
Cloud Computing Audit Program - ISACA

According to the ISACA Cloud Auditing Knowledge Certificate Study Guide, the auditor should review the relationship between the cloud service provider and its service provider to help direct and estimate the level of effort and analysis the auditor should apply1. The auditor should understand the nature and scope of the services provided by the service provider, the contractual obligations and service level agreements, the security and compliance requirements, and the monitoring and reporting mechanisms. The auditor should also assess the risks and controls associated with the service provider, and determine if additional audit procedures are needed to obtain sufficient assurance.
The other options are not the best approach for the auditor. Option A is too strict and might not be feasible or necessary, depending on the type and level of services provided by the service provider. Option C is too lax and might overlook significant risks and gaps in the cloud service. Option D is too narrow and might ignore the impact of the service provider on the cloud customer's business context. References:
* ISACA Cloud Auditing Knowledge Certificate Study Guide, page 13-14.

Explanation
The CSA STAR registry is a publicly accessible registry that documents the security and privacy controls provided by popular cloud computing offerings. The registry is based on the Cloud Controls Matrix (CCM), which is a framework of cloud-specific security best practices, and the GDPR Code of Conduct, which is a set of privacy principles for cloud service providers. The registry allows cloud customers to assess the security and compliance posture of cloud service providers, as well as to compare different providers based on their level of assurance. The registry also reduces the complexity and cost of filling out multiple customer questionnaires and requests for proposal (RFPs). Therefore, the best recommendation to reduce the provider's burden is to direct all customer inquiries to the information in the CSA STAR registry, which can demonstrate the provider's transparency, trustworthiness, and adherence to industry standards. The provider can also encourage customers to use the Consensus Assessments Initiative Questionnaire (CAIQ), which is a standardized set of questions based on the CCM, to evaluate the provider's security controls. Alternatively, the provider can pursue higher levels of assurance, such as third-party audits or continuous monitoring, to further validate their security and privacy practices and increase customer confidence.
References:
STAR Registry | CSA
STAR | CSA
CSA Security Trust Assurance and Risk (STAR) Registry Reaches Notable ...
Why CSA STAR Is Important for Cloud Service Providers - A-LIGN

Transparent data encryption (TDE) is used for data and log files at rest. This means that TDE encrypts the database files on the disk and decrypts them when they are read into memory. TDE protects the data from unauthorized access or theft if the physical media, such as drives or backup tapes, are stolen or lost. TDE does not encrypt data across communication channels, data currently being processed, or data in random access memory (RAM). These types of data require different encryption methods, such as SSL/TLS, column encryption, or memory encryption12.
References:
* Transparent data encryption (TDE) - SQL Server | Microsoft Learn
* Transparent Data Encryption - Oracle Help Center