Concept:Ad valorem import duty is calculated as a percentage of the goods' value, so the customs officer must verify the true value of the goods.Explanation:A consular invoice is a certified document issued by the importing country's consul in the exporting country. It states the exact description, quantity, and value of the goods being shipped. It is used by customs officials to confirm the declared value and compute the ad valorem duty correctly. Options like a bill of lading or shipping note are transport documents, not proof of value for duty purposes.Answer:D. consular invoice.