The best answer is B. Implementing cryptographic hash functions.
To ensure integrity, the organization needs a control that can detect unauthorized alteration. Cryptographic hash functions are specifically designed to verify that data has not been modified. Timestamping helps with sequencing and timing, limiting access helps reduce risk of tampering, and archiving helps retention, but hashing is the strongest direct method for validating integrity. This answer is standard ISACA-aligned control reasoning based on the security objective of integrity.
ISACA's log-management guidance emphasizes the need for trustworthy, purposeful logging and monitoring.
For log data to be trusted as evidence or for operations, it must be protected against undetected modification.
Among the given choices, cryptographic hashing is the most effective direct mechanism for that purpose.
References (Official ISACA):
* ISACA Journal, Log Management as an Enabler for Data Protection and Automated Threat Detection.
* ISACA Journal, A Framework for SIEM Implementation.

For an organization that has plans to implement web-based trading, it would be most important for an IS auditor to verify that the organization's information security plan includes security requirements for the new application. Security requirements are statements that define what security features and functions are needed to protect the confidentiality, integrity, and availability of the web-based trading application and its data.
Security requirements should be identified and documented during the planning phase of the application development life cycle, before any design or coding activities take place. Attributes for system passwords, security training prior to implementation, and firewall configuration for the web server are also important aspects of information security, but they are not as essential as security requirements for ensuring that the web- based trading application meets its security objectives.

The greatest challenge to the alignment of business and IT is the lack of chief information officer (CIO) involvement in board meetings. The CIO is the senior executive responsible for overseeing the IT strategy, governance, and operations of the organization, and ensuring that they support the business objectives and needs. The CIO should be involved in board meetings to communicate the value and contribution of IT to the organization, to align the IT vision and direction with the business strategy and priorities, and to advocate for the IT resources and investments required to achieve the desired outcomes. The lack of CIO involvement in board meetings can result in a disconnect between business and IT, a loss of trust and confidence in IT, and missed opportunities for innovation and value creation. The other options are not as challenging as the lack of CIO involvement in board meetings, because they either do not affect the strategic alignment of business and IT, or theycanbe addressed by other means such as collaboration, negotiation, or escalation. References: CISA Review Manual (Digital Version)1, Chapter 1, Section 1.2.1

The best way to ensure data integrity across system interfaces is to perform reconciliation. Reconciliation is the process of comparing and verifying the data from different sources or systems to ensure that they are consistent, accurate, and complete. Reconciliation can help to identify and resolve any discrepancies, errors, or anomalies in the data that could affect the quality, reliability, or validity of the information. Reconciliation can also help to detect and prevent any unauthorized or fraudulent data manipulation or modification. References:
CISA Review Manual (Digital Version)
CISA Questions, Answers and Explanations Database