What does a carnet allow merchandise to do?

A carnet is an international customs document that allows the temporary importation of goods without the need for customs duties or taxes in the countries visited. This specific characteristic of the carnet is what makes it particularly useful for items that are being brought into a country for purposes such as exhibitions, trade shows, or professional events, where the goods are intended to be re-exported afterward.

By possessing a carnet, the merchandise can indeed move free of entry, bond, and duty requirements, as long as the conditions of the carnet are met, including that the goods return to the origin country within a specified time frame. This reduces the burden on businesses and individuals by simplifying the customs process, allowing goods to move more freely across borders without the usual customs fees associated with importation.

In contrast, the other options mention different scenarios that don't accurately reflect the realities of what a carnet provides. For example, while a carnet allows for easier movement, it does not exempt goods from all tariffs or duty requirements unconditionally; rather, it allows temporary entry without these costs. Therefore, the correct understanding of the function of a carnet centers around its ability to enable the temporary movement of goods without the associated customs duties and requirements, which aligns directly with the highlighted answer.