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.

[Q]: Background Paragraph: Because of human activities, there is more carbon dioxide in the atmosphere today than in the past hundreds of thousands of years. Burning fossil fuels and has released great quantities of carbon dioxide into the atmosphere. Cutting forests and clearing land has also increased carbon dioxide into the atmosphere because these activities reduce the number of autotrophic organisms that use up carbon dioxide in photosynthesis. In addition, clearing often involves burning, which releases carbon dioxide that was previously stored in autotrophs.
Story: John has been hearing about climate change for last couple of years. He wants to understand the science behind climate change. For that, he picked up two eras in earth's history, era A and era B. Era A was hundred thousand years ago, and era B is in the present day. He now wants to compare these to eras to understand the change in climate better.
Question: Which era would have seen less fossil fuel burning, era A or era B?
[A]: era A.

[Q]: Background Paragraph: Hepatitis B is a contagious virus that affects the liver, infection can last from a few weeks to a serious lifelong illness. Two different types of infection exist for this disease, "acute" and "chronic." Acute Hepatitis B is a short term illness that occurs within 6 months of exposure, Chronic Hepatitis B is long term and happens when the virus remains in the body. The younger the child is, the greater their chance of developing a chronic infection and this risk goes down as the child gets older. Approximately 90% of infected infants will develop a chronic infection.[3].
Story: A 4th grade classroom photo was held today. They all gathered by age. Ahmed was the oldest. Jefferey was the 2nd oldest. Tyree was the 3rd oldest. Walker was the 4th oldest. Burl was the 5th oldest. Kip was the 6th oldest. The last one was Quinn, who was the youngest. They all looked wonderful that day.
Question: Who has a greater chance of developing a chronic infection: Walker or Kip?
[A]: Kip.

[Q]: Background Paragraph: Hepatitis B is a disease of the liver. It is caused by a virus called hepatitis B, which can be passed through sexual activity. Hepatitis B causes vomiting. It also causes yellowing of the skin and eyes. The disease goes away on its own in some people. Other people are sick for the rest of their lives. In these people, the virus usually damages the liver. It may also lead to liver cancer. Medicines can help prevent liver damage in these people. There is also a vaccine to protect against hepatitis B.
Story: Keith is a doctor in a local hospital. Today, he is seeing three patients, patient A, patient B, and patient C. Patient A has been suffering from hepatitis B all his life; patient B is recovering from hepatitis B on his own; and patient C doesn't have hepatitis B. Keith would now compare the symptoms of these patients.
Question: Which patient's symptoms would less likely include vomiting, patient A or patient C?
[A]:
patient C.