'Fly as thick as driving rain' is a simile because it uses the word 'as'.
Metaphors are like similes, but they don't have the words 'like' or 'as'.
Onomatopoeia may sound like a complicated word, but all it really means is a sound, like <em>BANG!</em>.
Personification is when a subject that's not human does something a person would do.
Your answer is a simile (B.). Hope this helps!
