I believe the correct answer is D. an old fish line hanging from its lip.
I don't think the other answers are correct - there was no garbage in its fins, no plastic in its teeth, and no fishhook in its eye. However, there were five old pieces of fish line in its lip, which means D is the correct answer.
1. By definition, a round character is a well-developed character.
2. If something is implied, that means it is stated indirectly.
3. Another word for exposition is introduction.
