You are given a background paragraph that describes one or more causal or qualitative relationships such as a relationship in economics or a scientific law and a story that makes use of the concepts or the relationship described in the provided paragraph. You are also given a question about the story that requires an understanding of the relationship described in the background paragraph and the story. You need to come up with an answer to the given question; the answer will be a span from either the question or the story. In order to correctly answer the given question, you need to understand the relationship mentioned in the background paragraph and should be able to use it to understand that in the story. Your answer can not consist of any word that is not mentioned in any of these: the background paragraph, the story, or the question. You can directly copy and paste a span from the story or the question while answering the given question.

Background Paragraph: Ocean acidification occurs when excess carbon dioxide in the atmosphere causes the oceans to become acidic. Burning fossil fuels has led to an increase in carbon dioxide in the atmosphere. This carbon dioxide is then absorbed by the oceans, which lowers the pH of the water. Ocean acidification can kill corals and shellfish. It may also cause marine organisms to reproduce less, which could harm other organisms in the food chain. As a result, there also may be fewer marine organisms for humans to consume. 
Story: Two islands were situated in different oceans. Hill island  used fossil fuels and released a lot of carbon dioxide into the atmosphere, while Coral island was very protective towards the air and the ocean. 
Question: Which island contributed more to ocean acidification?
Hill.

Background Paragraph: Hemophilia is the name of a group of hereditary diseases that affect the body's ability to control blood clotting. Hemophilia is caused by a lack of clotting factors in the blood. Clotting factors are normally released by platelets. Since people with hemophilia cannot produce clots, any cut can put a person at risk of bleeding to death. The risk of internal bleeding is also increased in hemophilia, especially into muscles and joints. This disease affected the royal families of Europe. 
Story: Czar Nicholas was the last Romanov who ruled Russia. Al along he was in good health, but that was not the case with his son Prince Alexei. While Nicholas was free from hemophilia, a disease that devastated European royal families, Alexei was born with hemophilia. Many suggest this situation made some opportunists to take advantage of the Czar. 
Question: Who would have more risk of bleeding to death, Nicholas or Alexei?
Alexei.

Background Paragraph: New species develop naturally through the process of natural selection . Due to natural selection, organisms with traits that better enable them to adapt to their environment will tend to survive and reproduce in greater numbers. Natural selection causes beneficial heritable traits to become more common in a population and unfavorable heritable traits to become less common. For example, a giraffe’s neck is beneficial because it allows the giraffe to reach leaves high in trees. Natural selection caused this beneficial trait to become more common than short necks. 
Story: Dan studied two islands. Loon island had a very stable environment, and there weren't many diverse species of plants and animals. Wolf island displayed lots of evidence for natural selection, and had a large variety of species inhabiting it. 
Question: Which island had animals that reproduced in greater numbers?

Wolf.