Suppose you traveled back in time and located the first animals to have developed feathers. You ...

Suppose you traveled back in time and located the first animals to have developed feathers. You found that these animals were ground-dwelling ectotherms, able to run quickly, but unable to fly or even glide. You also noticed that males of the species had no feathers at all, while females had bright blue feathers covering their tails. Which hypothesis of feather evolution would these data most support?
A) Feathers initially evolved to aid in flight.
B) Feathers initially evolved as a form of insulation.
C) Feathers initially evolved for use in courtship displays.
D) All of the above apply.