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.

[EX Q]: Background Paragraph: Iron is first oxidized to iron(II) ions by oxygen. In the second step, the iron(II) ions are further oxidized and combine with water and oxygen gas to produce a hydrated form of iron(III) oxide known as rust. Rusting is one of many example of corrosion. Corrosion is the deterioration of metals by redox processes. Corrosion causes enormous amounts of damage to buildings, bridges, ships, cars, and other objects. It has been estimated that corrosion costs the U.S. economy over 100 billion dollars each year. A great amount of time and effort is spent to try to limit or prevent corrosion. 
Story: Aaron is doing a science experiment for school. He is trying to see what happens to different iron objects in different conditions. He has two samples that he is testing. Sample A he has placed in a dark dry room away from the elements. Sample B he has placed outside under no cover, so it will be rained on. 
Question: Will Sample B be more or less likely to show signs of corrosion compared to Sample A?
[EX A]: more.

[EX 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. Justin was the oldest. Terry was the 2nd oldest. Gerald was the 3rd oldest. Keith was the 4th oldest. Samuel was the 5th oldest. Willie was the 6th oldest. The last one was Ralph, who was the youngest. They all looked great that day. 
Question: Who has a greater chance of developing a chronic infection: Gerald or Willie?
[EX A]: Willie.

[EX Q]: Background Paragraph: Old age begins in the mid-60s and lasts until the end of life. Most people over 65 have retired from work, freeing up their time for hobbies, grandchildren, and other interests. Stamina, strength, reflex time, and the senses all decline during old age, and the number of brain cells decreases as well. The immune system becomes less efficient, increasing the risk of serious illnesses such as cancer and pneumonia. Diseases such as Alzheimer’s disease that cause loss of mental function also become more common. 
Story: Doctor Brown examined two groups of patients: Group O, with members over 65, and group P, with members under 65 years of age. The study was about the effects on aging on the human body. 
Question: Which group has more people with declining reflex time?
[EX A]:
Group O.