The young man lost his way in the forest and found that he had become a/an . . . . . . . . . to the dacoits.

The correct answer is quarry.

A quarry is an animal that is hunted or pursued. In this case, the young man is being hunted by the dacoits.

The other options are incorrect because:

• An enemy is someone who is hostile or opposed to another person or group. The young man is not hostile to the dacoits, they are hostile to him.
• An adversary is a person who opposes or fights against someone. The young man is not fighting against the dacoits, they are fighting against him.
• A decoy is a person or thing used to attract attention away from something else. The young man is not being used to attract attention away from something else, he is the target of the dacoits’ attention.