The correct answer is Insects.
Insects were the first animals to evolve to fly. They did this by developing wings, which are made up of two pairs of membranous appendages. Insects use their wings to fly through the air, and they can also use them to control their flight.
Reptiles, mammals, and birds all evolved to fly later than insects. Reptiles developed wings from their forelimbs, and they use their wings to glide through the air. Mammals developed wings from their forelimbs, and they use their wings to fly short distances. Birds developed wings from their forelimbs, and they use their wings to fly long distances.
Insects are the most diverse group of animals on Earth. There are over 1 million different species of insects, and they can be found in almost every environment on Earth. Insects play an important role in the environment, and they are a valuable source of food for many animals.