The best process for continuous auditing for a large financial institution is validating access controls for real- time data systems. This is because access controls are critical for ensuring the confidentiality, integrity, and availability of the financial data that is processed and transmitted by the real-time data systems. Real-time data systems are systems that provide timely and accurate information to support decision-making and transactions in a dynamic and complex environment. Examples of real-time data systems in the financial sector include payment systems, trading platforms, risk management systems, and fraud detection systems.
Continuous auditing of access controls can help detect and prevent unauthorized access, data leakage, data manipulation, or data loss that could compromise the security, reliability, or compliance of the real-time data systems.
Testing encryption standards on the disaster recovery system is not the best process for continuous auditing for a large financial institution. Encryption standards are important for protecting the data stored or transmitted by the disaster recovery system, which is a system that provides backup and recovery capabilities in case of a disruption or disaster. However, testing encryption standards is not a continuous process, but rather a periodic or event-driven process that can be performed as part of the disaster recovery plan testing or validation.
Performing parallel testing between systems is not the best process for continuous auditing for a large financial institution. Parallel testing is a process of comparing the results of two or more systems that perform the same function or task, such as a new system and an old system, or a primary system and a backup system.
Parallel testing can help verify the accuracy, consistency, and compatibility of the systems. However, parallel testing is not a continuous process, but rather a temporary or transitional process that can be performed as part of the system implementation or migration.
Validating performance of help desk metrics is not the best process for continuous auditing for a large financial institution. Help desk metrics are indicators that measure the efficiency, effectiveness, and quality of the help desk service, which is a service that provides technical support and assistance to the users of information systems and technology. Help desk metrics can include metrics such as response time, resolution time, customer satisfaction, and service level agreement (SLA) compliance. Validating performance of help desk metrics can help evaluate and improve the help desk service. However, validating performance of help desk metrics is not a continuous auditing process, but rather a continuous monitoring process that can be performed by the help desk management or quality assurance team.
References:
* All eyes on: Continuous auditing - KPMG Global 1
* Internal audit's role at financial institutions: PwC 2
* The Fed - Supervisory Policy and Guidance Topics - Large Banking ... 3
* Continuous Audit: Definition, Steps, Advantages and Disadvantages 4

A three-way match is a process of verifying that a purchase order, a goods receipt and an invoice are consistent before making a payment1. A three-way match ensures that the organization only pays for the goods or services that it ordered and received, and that the prices and quantities are accurate. A three-way match can prevent errors, fraud and overpayments in the accounts payable process.
An IS auditor should use a purchase order when verifying a three-way match has occurred in an enterprise resource planning (ERP) system. A purchase order is a document that authorizes a purchase transaction and specifies the items, quantities, prices and terms of the order2. A purchase order is the first document in the three-way match process, and it serves as the basis for comparing the goods receipt and the invoice. An IS auditor can use a purchase order to check if the ERP system has correctly recorded, matched and approved the three documents before making a payment.
The other options are not as useful for verifying a three-way match. A bank confirmation is a document that verifies the balance and activity of a bank account3. A bank confirmation can be used to confirm that a payment has been made or received, but it does not provide information about the details of the purchase transaction or the three-way match process. A goods delivery notification is a document that informs the buyer that the goods have been shipped or delivered by the seller4. A goods delivery notification can be used to track the status of the delivery, but it does not provide information about the quantity or quality of the goods or the invoice amount. A purchase requisition is a document that requests authorization to purchase goods or services from a specific supplier2. A purchase requisition can be used to initiate the purchasing process, but it does not provide information about the actual purchase order, goods receipt or invoice.
References:
Bank Confirmation - Overview, How It Works, Importance3
What is Goods Delivery Note? | Definition & Example4
What Is Three-Way Matching & Why Is It Important? | NetSuite1
Enterprise Resource Planning (ERP) - Definition, Types, Uses2

A risk and control framework is a set of principles, processes, and tools that guide an organization in identifying, assessing, managing, and monitoring the risks and controls that affect its objectives and performance. A risk and control framework helps an organization to align its risk appetite and tolerance with its strategy, culture, and values, and to ensure that its security controls are appropriate, effective, and efficient1.
Re-evaluating the organization's risk and control framework is the best recommendation to management because it can help them to:
Review the current risk environment and the sources, causes, and impacts of potential threats and vulnerabilities.
Update the risk assessment and analysis methods and criteria, such as likelihood, impact, severity, and priority.
Reconsider the risk response and treatment options, such as avoidance, reduction, transfer, or acceptance.
Realign the security controls with the risk profile and the business needs and expectations.
Evaluate the performance and effectiveness of the security controls using key indicators and metrics.
Identify the gaps, weaknesses, or inefficiencies in the security controls and implement corrective or improvement actions.
Communicate and report the risk and control status and results to relevant stakeholders.
Re-evaluating the organization's risk and control framework can help management to determine whether the current security controls are excessive or not, and to make informed and rational decisions on how to adjust them accordingly.