Well all of these answer choice technically could be correct, (Depending on the circumstances) but the most logical answer is wings to fly. without wings to fly how would they escape a dangerous situation? but lets just say what if the bird couldn't fly? the most logical answer would be dark colors because the bird has the ability to conceal itself from predators because of the dark colors. like I said before, all of these answer choice would technically be correct but the correct answer is D) WINGS TO FLY!!!!!!
Hope I was able to help,~kashout kam
