Simile. "They look like white elephants" is a simile because it is a comparison using the word like. A metaphor would say something is something else, alliteration is the repetition of a beginning sound, and personification gives something human-like characteristics.
Answer:
Idiom
Explanation:
a simile uses like or as, alliteration is simalar sounding words like a "tongue twister" therefore it would be idiom :)
I would go with barb, think of a barbed wire fence and then think of the tip of the arrow. It makes the best match.
