I think your answer will be C.
To create a better image in the reader's mind. The use of imagery creates a better picture when the reader imagines the setting. Since when reading everyone thinks of a different picture imagery helps to create a picture closer to what the author imagined.
The correct answer to that is obvious
It’s
The topic of the paragraph
The Universal theme is that there is always a bright side to life not meant with riches. The first poem states that every cost of a life is worth something. Second poem is grief about the lost ones who sacrificed their lives.