The suggested answer is D.
Internal auditors, according to the International Professional Practices Framework, should possess proficiency in applying internal auditing standards, procedures, and techniques (I). They should also have an understanding of management principles (III) and an understanding of the fundamentals of economics, commercial law, taxation, finance, and quantitative methods (IV). While proficiency in accounting principles and techniques (II) is more specifically required for accountants, internal auditors should have a broader understanding across various domains. Therefore, the correct competencies align with options I, III, and IV.