Answer:
C) Modern species share a common ancestor
Step-by-step explanation:
The present-day species are supposed to have evolved as descent with modification from a common ancestor. The descendants of common ancestors diversified into several directions to occupy the available ecological niche and to make themselves adapted to the different habitats. Accumulation of adaptive traits in these groups of organisms led to the evolution of different species.
Different groups of birds have evolved by divergent evolution in the descendants of common reptilian ancestors. Connecting links such as Archaeopteryx that share features from two different groups of organisms reflect the fact that the existing species that differ from each other significantly might have shared a common ancestor during their course of evolution.