It cannot be:
Simile: involving the comparison of one thing with another thing.
Example: He/She is as brave as a lion
Methaphor: refers to something as being the same as another thing for rhetorical effect.
Example: The classroom was a zoo.
Between the last 2 options:
Remember that alliteration is: a stylistic literary device identified by the repeated sound of the first consonant in a series of multiple words, or the repetition of the same sounds or of the same kinds of sounds at the beginning of words or in stressed syllables of a phrase.
Example: But a better butter makes a batter better.
This is an alliterative because the same first letter of words (B) occurs close together and produces alliteration in the sentence.
While... Repetition is: Repetition is a literary device that repeats the same words or phrases a few times to make an idea clearer.
Example: I looked upon the rotting sea,
And drew my eyes away;
I looked upon the rotting deck,
And there the dead men lay.
So between both the one that makes more sense is Alliteration.
