If a Boy Falls Off a Swing and Breaks His

If a boy falls off a swing and breaks his arm it will heal, however if a dragonfly breaks a wing it cannot be repaired. What explains the difference?

A) The chitin in the boy is a flexible form that can be repaired.
B) Dragonfly wings are made of a rigid form of collagen.
C) Bone contains living cells, chitin is acellular.
D) Bones are only repairable in children.