challenge: How do band cusk eels reproduce, given that males lack copulatory organs?
  
  A. Internal fertilization of eggs, which are then brooded by the female
  B. Sequential hermaphroditism, where individuals change sex from female to male as they mature
  C. External fertilization of eggs, which are then kept together in gel-like clumps near the surface
  D. Ovoviviparity, where eggs hatch inside the mother's body and the young are nourished by a yolk sac
  Answer: 