The answer is the 3rd one.
The answer is B.The swan is a personification of death and dying even when it is not a person.The swan and the particular behaviour it has in the situation here, proves to be that of the act of dying , the moment when death becomes it all.It cannot be a metaphor because it is not implying a resemblance with an object or thing.It is not a simile because we do not have two things being compared with a <em>it is like...</em>Finally it is not a hyperbole because there is no exaggeration at anything resembling a swan.
