The correct answer is A) Archeopterix is the connecting link between birds and reptiles which shows that birds and reptiles are related.
Birds have been reclassified as reptiles. The line of evidence that has led to this reclassification is "Archeopterix is the connecting link between birds and reptiles which shows that birds and reptiles are related."
Scientists had done extensive research in China and South America and found a connection between reptiles and birds when they discovered the fossil of the Archeopterix in 1860. It had feathers in arms and a tail but had teeth. So the Archeopterix was recognized as an intermediate between reptiles and birds.
The other options of the question were B) birds have scales, so they have the same origin as reptiles. C) birds and reptiles have the same circulatory and excretory system and both are egg-lay animals. D) Birds and reptiles have similar anatomical and morphological features.