Answer:
Benvolio tells the Prince the story of the brawl, emphasizing Romeo's attempt to keep the peace, but Lady Capulet, Tybalt's aunt, cries that Benvolio is lying to protect the Montagues. She demands Romeo's life.
'Before they ate a snack' is the correct answer, it is the adverbial clause of time. A cannot be correct because that is an independent clause, and adverb clause has to be dependent. B isn't a clause at all.
