Which literary device does Dickinson begin with the phrase "setting sun"? alliteration metaphor personification sarcasm

A metaphor is comparing two unlike objects without the use of the words like or as. Metaphors are usually symbolic. An alliteration is a group of words that have similar letters or sounds. Personification is giving an inanimate object the characteristics that a person would have. Sarcasm is the use of irony to mock. You must decide from here.