Final answer:
The concept being addressed is materiality in financial auditing, and the correct answer is that 'materiality to the auditor's opinion' is not a proper concern when determining if a misstatement is qualitatively material.
Step-by-step explanation:
The question concerns the concept of materiality in the context of financial auditing. Materiality is a threshold for how much a misstatement can distort the financial information to influence the decision-making of users. When assessing if a misstatement is materially significant, it's important to consider its impact on the financial statements as a whole and on individual financial statement items. However, the materiality to the auditor's opinion is not the right concern because the quality of the auditor's opinion is predicated on the correctness of the financial statements, not the other way around. Therefore, the correct answer is that 'materiality to the auditor's opinion' is not a proper concern in regards to whether a misstatement is qualitatively material.