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.
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Question: Background Paragraph: Air pollution is harmful to human beings and other living things. About 22 million people die from air pollution each year. Breathing polluted air increases the risk of developing lung diseases such as asthma and lung cancer. Breathing bad air also increases the chances of dying from other diseases. Children are most likely to be affected by air pollution. That’s because their lungs are still developing and growing. Children also take in more air for their size than adults do. Some air pollutants damage the environment as well as the health of living things. The type of damage depends on the pollutant. Air pollution can also harm the environment. 
Story: Sarah and Sophie are sisters living in two different cities. Sarah lives in a very rural area with hardly any air pollution. Sophie lives in a heavily industrialized urban area with many factories and people driving cars to their destinations. This all leads to Sophie's city having a large amount of pollution going into the atmosphere. 
Question: Will the percentage of people with asthma be lower in Sophie's city or Sarah's city?

Answer: Sarah's city.


Question: 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?

Answer: Willie.


Question: Background Paragraph: Weather conditions include air temperature, humidity, wind speed and direction, and precipitation. Weather is temporary. People in many states have the joke, "if you don't like the weather, wait five minutes and it will change." One way to change the weather is to have a different air mass move over the region. Interactions between air masses bring about a lot of weather. For example, thunderstorms and tornadoes form along a front. A front is where air masses meet. Fronts can bring about blizzards, thunderstorms, tornadoes and other types of weather. Weather prediction is much better than it was in past years. This is due in part to information from satellites. Climate is the long-term average of weather. The climate of a location depends on its latitude, position relative to the atmospheric circulation cells, position on a continent, altitude, and position relative to mountains. Areas with roughly the same climate make up a climate zone. The organisms that live within a climate zone create a unique biome. Earth's climate has changed throughout the planet's history. Earth was frigid at the end of the Pleistocene ice age, but has been warming since then. Since the Industrial Revolution the pace of warming has increased. In the past few decades the rate has really intensified. This is related to greenhouse gas emissions, primary from fossil fuel burning. The destruction of forests also increasing warming. The effects of global warming are already being seen. Treaties and voluntary actions are needed to reduce emissions to lessen the amount of global warming that will take place in the future. 
Story: Rob always confuses the terms climate and weather. He found it's better to compare them if he needs to learn more about their characteristics. To make things easier, he labeled the weather of his city as char A. Then he labeled the climate of this city as char B. Once finished with learning their characteristics, Rob focused on climate change issues. For that, he labeled the climate of present time as char C and climate just before industrial revolution as char D. 
Question: Which one denotes shorter time period, char A or char B?

Answer:
char A.