Change control is the process of managing and documenting changes to an information system or its components. Change control aims to ensure that changes are authorized, tested, approved, implemented, and reviewed in a controlled and consistent manner. Change control is an essential part of ensuring the security, reliability, and quality of an information system.
One of the key elements of change control is testing and approval from quality assurance (QA). QA is the function that verifies that the changes meet the requirements and specifications, comply with the standards and policies, and do not introduce any errors or vulnerabilities. QA testing and approval provide assurance that the changes are fit for purpose, function as expected, and do not compromise the security or performance of the system.
An organization that has recently moved to an agile model for deploying custom code to its in-house accounting software system should still follow change control procedures, including QA testing and approval.
Agile development methods emphasize flexibility, speed, and collaboration, but they do not eliminate the need for quality and security checks. In fact, agile methods can facilitate change control by enabling frequent and iterative testing and feedback throughout the development cycle.
However, if change control does not include testing and approval from QA, this poses a significant security concern for the organization. Without QA testing and approval, the changes may not be properly validated, verified, or evaluated before being deployed to production. This could result in introducing bugs, defects, or vulnerabilities that could affect the functionality, availability, integrity, or confidentiality of the accounting software system. For example, a change could cause data corruption, performance degradation, unauthorized access, or data leakage. These risks could have serious consequences for the organization's financial operations, compliance obligations, reputation, or legal liabilities.
Therefore, change control that does not include testing and approval from QA is the most significant security concern to address when reviewing the procedures in place for production code deployment in an agile model.
References:
* Change Control - ISACA
* Quality Assurance - ISACA
* Agile Development - ISACA
* 10 Agile Software Development Security Concerns You Need to Know

The best recommendation for improving IT governance within the organization is to implement key performance indicators (KPIs). KPIs are measurable values that show how effectively the organization is achieving its key business objectives. KPIs can help the organization to monitor and evaluate the performance, efficiency, and alignment of its IT processes and resources with its business goals and strategies1.
The other options are not as effective as implementing KPIs for improving IT governance. Option B, implementing annual third-party audits, is a good practice but may not be sufficient or timely to identify and address the issues or gaps in IT governance. Option C, benchmarking organizational performance against industry peers, is a useful technique but may not reflect the specific needs and expectations of the organization's stakeholders. Option D, requiring executive management to draft IT strategy, is a necessary step but not enough to ensure that IT governance is implemented and monitored throughout the organization.

Stress testing is designed to evaluate a system's performance under extreme conditions1. It is typically carried out in a test environment that closely mirrors the production environment, using production workloads1. This approach ensures that the test results accurately reflect how the system would perform under similar conditions in the production environment1. Using a test environment also prevents any disruptions or damage to the production environment during testing1.
References:
Stress Testing Best Practices: A Seven Steps Model