Concept:Tramp ships are cargo vessels without fixed routes or schedules.
Explanation:A tramp ship operates like an on-demand cargo carrier.
It does not follow a regular timetable or a fixed sea route.
Instead, it sails to any port where cargo is available for loading.
It also travels at any time whenever shipping services are required.
This flexibility makes tramp ships suitable for carrying bulk or general cargo based on market needs.
Ferries operate on fixed short routes, tankers carry liquid cargo, and steamers refer generally to steamships.
Therefore, the correct option is the vessel described as a tramp.
Answer:C. tramps