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: The ozone layer is contained within the stratosphere. In this layer ozone concentrations are about 2 to 8 parts per million, which is much higher than in the lower atmosphere but still very small compared to the main components of the atmosphere. It is mainly located in the lower portion of the stratosphere from about 15–35 km (9.3–21.7 mi; 49,000–115,000 ft), though the thickness varies seasonally and geographically. About 90% of the ozone in Earth's atmosphere is contained in the stratosphere. 
Story: The ozone layer helps organisms by protecting them from Sun's ultraviolet radiation. To find the usefulness of ozone layer Mike wanted to see how much ozone are there in the atmosphere. He then collected three samples of atmosphere, sample A sample B, and sample C. Sample A was collected from the upper portion of the stratosphere. Sample B was collected from the lower portion of the stratosphere. Sample C was collected from the lower atmosphere. 
Question: Which sample's layer would protect less from ultraviolet radiation, sample A or sample B?
[EX A]: sample A.

[EX Q]: Background Paragraph: Alberta's electrical demand varies throughout the day and across the seasons. When individuals are fixing supper and using home appliances, demand for power goes up, as it does during heat waves and cold snaps. It tapers off during spring and fall. Like other mechanical devices, generators fail from time to time. If they are wind-powered, their output varies with the wind. 
Story: Horus works at the power plant in Alberta. He is charged with varying which generators to turn on for various power demands. His boss has informed him that he wants Horus to be as efficient as possible, and to only use the generators when needed, otherwise to have them off. Horus has been trained to recognize different conditions, such as hot temperatures, cold temperatures, moderate weather, and time of the day, such as late at night, early mornings, or the evenings, as all having different power demands. 
Question: Will the demand for power be higher or lower in the evening than late at night?
[EX A]: higher.

[EX Q]: Background Paragraph: Many chemicals that were once commonly used were later found out to be harmful to the environment , to human health, or both. The element lead was once a common additive to gasoline and to paint. Plumbing pipes were once typically made of lead. Only since the 1970s has the danger of lead become apparent. It causes brain damage and small children (who often chewed on objects painted with lead-based paint) are particularly susceptible. The use of lead in gasoline, paint, and plumbing pipes is now banned and new materials are being developed to replace the hazardous lead components. 
Story: John is trying to buy a house. Today, he saw two houses, house A and house B. House A was build in the 1920s. It has lead plumbing pipes and lead based paint. House B was build recently. It does not have lead plumbing pipes or lead based paint. 
Question: Which house would more likely cause brain damage, house A or house B?
[EX A]:
house A.