Final answer:
The correct answer to the question of which one is a water transport is a a. submarine, as it is designed to operate under water.
Step-by-step explanation:
The question Which one is a water transport? pertains to various modes of transportation. The correct answer is a. submarine, which is indeed a water transport vehicle.
Submarines are specially designed to move under water, and they can adjust their density using ballast tanks allowing them to float or sink as desired.
Unlike bicycles, hot air balloons, or trains, submarines are inclusive in voyaging through water environments and are an integral part of naval fleets, especially considering their military use introduced during World War I by the British.
Unlike other vehicles which may travel on trails, roadsides, or through the air, submarines operate entirely in aquatic environments.