Here's a problem to solve: Stout beardfish live in the deep ocean. They live so far down that there is no light. Which characteristic would best help stout beardfish to survive in the dark?

Among the 4 following options, which is the correct answer?

- A: a mouth full of bristles
 
- B: a brightly colored body
 
- C: the ability to swim quickly
 
- D: two whiskers that locate food
 