The correct answer is option 1: birds from reptiles. The fossil of Archaeopteryx provides evidence for the origin of birds from reptiles.

Archaeopteryx is a well-known fossil that lived during the late Jurassic period, about 150 million years ago. It is considered a transitional fossil, showing characteristics of both reptiles and birds.

The fossil has feathered wings similar to those of modern birds, suggesting it had the ability to fly. However, it also possesses reptilian features such as teeth, a long bony tail, and claws on its wings. This combination of features provides evidence that birds evolved from reptiles, specifically from a group of small, carnivorous dinosaurs known as theropods.

The presence of feathers in Archaeopteryx supports the theory of avian evolution from reptiles. It indicates a step towards the development of flight and displays a transition from scales to feathers. This fossil is considered crucial in understanding the evolution of birds and their connection to reptiles.

Therefore, the correct option is 1: birds from reptiles.