Final answer:
An auditor should assess supplementary financial disclosures for pension information required by GASB for compliance, given their importance in providing transparency and information about the entity's pension obligations.
Step-by-step explanation:
When an auditor determines that an entity is presenting certain supplementary financial disclosures of pension information that are required by the Governmental Accounting Standards Board (GASB), the appropriate course of action is to assess the presentation and disclosure for compliance with GASB requirements. This is because these disclosures are critical in providing transparency regarding the pension plans and their funding levels, which can affect both the entity's financial health and the beneficiaries of these pension plans. Such an assessment should focus on the accuracy and completeness of the information provided, ensuring that these disclosures give a fair view of the entity's pension obligations.