Answer:
Metaphor
Step-by-step explanation:
Personification, is when a thing, object or animal, receives human attributes. This figurative language does not have relation with the line we are analyzing.
Symbol or symbolism is when the author uses and object or action to represent something else, common symbolism are like a dove that represents peace or a red rose that is associated with love. King did not establish the radiant stars as a specific symbol of love and brotherhood.
Simile, is when the author compared two things using the word like or as, an example would be brotherhood like radiant stars, however, King shows the similarity between “the love and brotherhood”, and “the radiant stars” implied in the text, we infer that “the love and brotherhood” are like “radiant stars” this comparison is knows as Metaphor.