The audit team's most important course of action is to consult the legal department to understand the procedure for requesting data from a different jurisdiction, as this will ensure that the data analytics techniques are compliant with the applicable laws and regulations of both countries12. Requesting data from a foreign branch may involve legal risks such as data privacy, data sovereignty, and data protection34, and the audit team should seek legal guidance before proceeding with the data extraction and analysis.
References
1: Data Analytics and Auditing Standards 2: Data Analytics and the Audit Process 3: Data Privacy and Data Protection: US Law and Legislation 4: Data Sovereignty: What It Is and Why It Matters

Regression testing is the most appropriate testing method for assessing whether system integrity has been maintained after changes have been made. Regression testing is a type of software testing that ensures that previously developed and tested software still performs as expected after a change1 Regression testing helps to detectany defects or errors that may have been introduced or uncovered due to the change2 Regression testing can be performed at different levels of testing, such as unit, integration, system, and acceptance3 Unit testing is a type of software testing that verifies the functionality of individual components or units of code. Unit testing is usually performed by developers before integrating the code with other components. Unit testing helps to identify and fix errors at an early stage of development, but it does not ensure that the system as a whole works as expected after a change.
Integration testing is a type of software testing that verifies the functionality, performance, and reliability of the interactions between different components or units of code. Integration testing is usually performed after unit testing and before system testing. Integration testing helps to identify and fix errors that may occur when different components are integrated, but it does not ensure that the system as a whole works as expected after a change.
Acceptance testing is a type of software testing that verifies whether the system meets the user requirements and expectations. Acceptance testing is usually performed by end-users or customersafter system testing and before deploying the system to production. Acceptance testing helps to ensure that the system delivers the desired value and quality to the users, but it does not ensure that the system as a whole works as expected after a change.
References: 1: What is Regression Testing? Test Cases (Example) - Guru99 2: What is Regression Testing? Definition, Tools, Examples - Katalon 3: Regression testing - Wikipedia : What is Unit Testing?
Definition, Types, Tools & Examples - Guru99 : What is Integration Testing? Definition, Types, Tools & Examples - Guru99 : What is Acceptance Testing? Definition, Types, Tools & Examples - Guru99