The internal auditor demonstrated due professional care by deciding to remove a test from the audit work program when the cost outweighed the benefit. Due professional care involves considering the efficiency and cost-effectiveness of audit procedures in relation to the potential benefits. This decision shows prudent judgment and a focus on optimizing the value of audit activities. References: Institute of Internal Auditors (IIA) - International Professional Practices Framework (IPPF)

According to IIA guidance, the primary reason the chief audit executive discusses the internal audit charter with senior management and the board is to provide an understanding of the Mission of Internal Audit and The IIA's mandatory guidance elements. The charter defines the purpose, authority, and responsibility of the internal audit activity, aligning it with the organization's objectives and governance.
The IIA's International Professional Practices Framework (IPPF) particularly emphasizes the importance of the internal audit charter as a foundational document.

According to IIA guidance, business ethics may indeed vary within an organization with both domestic and foreign operations. This variation is due to differing cultural norms, legal requirements, and business practices across countries, which may necessitate adaptations in ethical policies and practices. While the core principles of ethics might be universally upheld, their application can differ based on local contexts.
Institute of Internal Auditors (IIA) - Code of Ethics, International Professional Practices Framework (IPPF)

The chief audit executive's most likely concern regarding a candidate who most recently worked for a large public accounting firm is the potential conflict of interest. This is particularly relevant if the candidate was involved in auditing the organization or its competitors, or if they have relationships that could influence their objectivity.
IIA Code of Ethics and Standards on Objectivity

The board manages the process of developing, approving, and executing the strategic plan of the organization to ensure adequate governance. This responsibility includes aligning the strategic plan with the organization's goals and monitoring its execution, which is a key governance role.
Corporate governance principles; IIA guidance on the role of the board in strategic planning.