【单选题】

When you transport your goods internationally, several precautions must be taken to ensure proper shipment:Export shipments require greater handling than domestic transport and should be properly packaged and correctly documented so that they arrive safely and on time. You also need to make sure that breakable items are protected, and that other fragile goods will not be damaged by the stresses of air and ocean shipment, such as vibration and moisture.

You must first decide what mode of transport is best. When shipping within a continent, you may prefer land transportation. When shipping to another continent, the preferred method may be by sea or air.Although maritime shipping is general]y less expensive than air, it can be much slower and thus less cost-effective. You should consider the additional costs of sea freight, such as surface transportation to and from the docks and port charges. Ocean freight can take longer than air freight and you may have to wait until the ship reaches its destination to receive payment.
According to the document, shipping by sea usually:
A、is best
B、costs more
C、is faster
D、costs less