Encrypting the data would MOST effectively reduce the risk associated with inadvertent disclosure of database records from a public cloud service provider (CSP), because it is a control that protects the confidentiality and integrity of the data by transforming it into an unreadable and unmodifiable form, using a secret key or algorithm. Encrypting the data can prevent or minimize the unauthorized or accidental access, modification, or leakage of the data, especially when the data is stored, transmitted, or processed in a public cloud environment, which may have less security and control than a private or on-premise environment. The other options are not as effective as encrypting the data, because:
Option B: Including a nondisclosure clause in the CSP contract is a legal measure that can deter or penalize the CSP from disclosing the data to any third party, but it does not reduce the risk of inadvertent disclosure of the data, which may occur due to human error, system failure, or malicious attack, and it does not protect the data from unauthorized or accidental access, modification, or leakage.
Option C: Assessing the data classification scheme is a process that can help to identify and categorize the data according to its sensitivity, value, and criticality, and to determine the appropriate level of protection and handling for the data, but it does not reduce the risk of inadvertent disclosure of the data, which may affect any type or class of data, and it does not provide the specific or effective control to protect the data from unauthorized or accidental access, modification, or leakage.
Option D: Reviewing CSP access privileges is a procedure that can help to monitor and verify the access rights and permissions of the CSP to the data, and to ensure that they are aligned with the business needs and expectations, but it does not reduce the risk of inadvertent disclosure of the data, which may occur even with the legitimate or authorized access of the CSP, and it does not protect the data from unauthorized or accidental access, modification, or leakage by otherparties. References = Risk and Information Systems Control Study Manual, 7th Edition, ISACA, 2020, p. 211.