Answer:
Because his mom and sisters are dead, also because he's the only one from his family that is left.
Explanation:
The correct answer is metaphor.
A metaphor is a rhetorical figure of speech where two or more things are symbolically compared, without using the words such as like or as (because that would be a simile). This whole poem is symbolical/metaphorical - it talks about the passage of time and how everything is transient and fleeting.
Blue, and
pasture,
the native grasses,
Disappointed,
I may be wrong but it sounds right and looks right.