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: For example, a radioactive isotope of iodine (I-131) is used in both the diagnosis and treatment of thyroid cancer. The thyroid will normally absorb some iodine to produce iodine-containing thyroid hormones. An overactive thyroid gland will absorb a larger amount of the radioactive material. If this is the case, more and more radioactive iodine can be administered, where it will cluster in the diseased portion of the thyroid tissue and kill some of the nearby cells. Cancer treatments often cause patients to feel very sick, because while the radiation treatment kills the unwanted cancer cells, it causes damage to some healthy cells in the process. 
Story: John is a doctor in a local hospital. Today, he is seeing two patients, patient A and patient B. Patient A has thyroid cancer, but patient B does not have thyroid cancer. John is trying to see the difference between these two patients' reports. 
Question: Which patient would have an overactive thyroid gland, patient A or patient B?
patient A.

Background Paragraph: Allergy symptoms can range from mild to severe. Mild symptoms might include itchy eyes, sneezing, and a runny nose. Severe symptoms can cause difficulty breathing, which may be life threatening. Keep in mind that it is the immune system and not the allergen that causes the allergy symptoms. Allergy symptoms can be treated with medications such as antihistamines. Severe allergic reactions may require an injection of the hormone epinephrine. These treatments lessen or counter the immune system’s response. 
Story: Two groups of  students went to the forest to explore nature and learn botany. Group D had some people experiencing mild allergy symptoms, and group C had a few folks with severe allergy symptoms, so they had to call the ambulance asap. 
Question: Which group had fewer people that could be treated with antihistamines?
group C.

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 3rd grade classroom photo was held today. They all gathered by age. Charles was the youngest. Joseph was the 2nd youngest. Thomas was the 3rd youngest. Christopher was the 4th youngest. Daniel was the 5th youngest. Paul was the 6th youngest. The last one was Mark, who was the oldest. They all looked fantastic that day. 
Question: Who has a greater chance of developing a chronic infection: Paul or Charles?

Charles.