The correct answer is: A. Customs
A bill of entry is a document that is used to declare goods that are being imported or exported. It is used to calculate the amount of duty that is payable on the goods. The auditor will examine the bill of entry to verify that the correct amount of duty has been paid.
Income tax is a tax that is levied on the income of individuals and businesses. It is a major source of revenue for governments. The auditor will examine the income tax returns to verify that the correct amount of tax has been paid.
GST is a value-added tax that is levied on goods and services. It is a major source of revenue for governments. The auditor will examine the GST returns to verify that the correct amount of GST has been paid.
VAT is a value-added tax that is levied on goods and services. It is a major source of revenue for governments. The auditor will examine the VAT returns to verify that the correct amount of VAT has been paid.
However, in the context of a bill of entry, the only relevant expense is customs duty. Therefore, the correct answer is A.