The answer is B. Sailed.
The other three words, travelled, walked, and rode, all refer to ways of moving from one place to another on land. Sailed, on the other hand, refers to a way of moving from one place to another on water.
Travelled is the most general word, and can refer to any way of moving from one place to another. Walked refers to moving on foot, while rode refers to moving on horseback or in a vehicle. Sailed refers to moving on a boat or ship.
In the context of the question, the word that is different from the rest is B. Sailed. This is because the other three words, travelled, walked, and rode, all refer to ways of moving from one place to another on land. Sailed, on the other hand, refers to a way of moving from one place to another on water.