To assist the board of directors in understanding the degree of ethics awareness within the organization, an organization-wide employee survey on ethical practices (option D) is the most effective action. Here's why:

Direct Insight from Employees: Surveys can capture the perspectives of a broad employee base, providing direct insights into the awareness and attitudes towards ethics within the organization.

Quantitative and Qualitative Data: A well-designed survey can gather both quantitative data (e.g., percentage of employees aware of the code of ethics) and qualitative data (e.g., specific instances of ethical dilemmas faced by employees).

Identifying Areas of Improvement: Surveys can identify specific areas where employees feel the organization is lacking in terms of ethical practices, which can guide targeted improvements.

Confidentiality and Anonymity: Surveys often ensure confidentiality and anonymity, encouraging more honest and comprehensive responses from employees, which might not be achievable through other means.

Comprehensive Scope: Compared to internal audits or training, surveys can provide a comprehensive overview of the entire organization’s ethical climate, from various departments and levels.

This approach aligns with the best practices in internal auditing and organizational assessments as outlined by the Institute of Internal Auditors (IIA) and other related guidance​​.