I'd say it should be D. Peat. Hope this helps! =^-^=
D. the floodplain shrinks
Answer:
Due to presence of these structures in ancient as well as modern organisms.
Explanation:
Homologous and vestigial structures are the evidences that show evolutionary relationships between organisms because these structure were also present in the ancient ancestor of that organism. These homologous and vestigial structures shows the relationship between the ancient and the modern organisms. Some structure has a purpose and function in the body of ancient organisms but with the passage of time those structure are useless and have no function in the body but these structure shows connection between modern and ancient organisms.
I apologize in advance if this is incorrect but what I was taught is that the correct answer is gather data to design a recovery plan.