Answer:
The correct answer is Simile.
Step-by-step explanation:
A simile is used in literature to compare a real element and another imaginary or figurative one. In this case the narrator compares himself with the sea-bird by saying that he is sad like the bird. The difference between this tool and a metaphor is that the simile uses words like "like" or "as".
In this way, the simile makes it possible to connect different elements in a simple and effective way to offer a new way of seeing or understanding a certain thing, since it operates by transferring the characteristics or features, symbolic or evident, from one thing to another.