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: Before iodized salt was developed, some people experienced a number of developmental difficulties, including problems with thyroid gland function and mental retardation. In the 1920s, we learned that these conditions could usually be treated easily with the addition of iodide anion to the diet. One easy way to increase iodide intake was to add the anion to table salt. This simple step greatly enhanced health and development. Large amounts of iodide ion are also found in seaweed such as kelp (see picture above) and saltwater fish. 
Story: People from two villages ate lots of salt. People from Salt village used regular salt, while people from Sand village people used iodized salt in their diets, after talking to specialists. 
Question: Which village had more people experience developmental difficulties?

Answer: Salt.


Question: Background Paragraph: Artworks are sold at affordable prices [6] ranging from £5 to £1500. For many of the works, the price goes up as the edition sells out. The edition runs range from 30 to 10,000 editions. Each work comes with a digital certificate that is “signed, numbered and authenticated by the artist” [7][8] Once an edition is sold out, collectors can resell their works in the online marketplace. 
Story: The prices of John's paintings started to rise immediately after the edition sold out. they used to cost $10 but now they sell for at least $200. john had 45 paintings in this edition. The prices of Mike's paintings are at $8 a piece, because his edition hasn't sold out yet. Mike's edition run was 250 editions. 
Question: Which paintings sold for more money before they sold out?

Answer: John's.


Question: Background Paragraph: If a zone undergoes dramatic changes in temperature with depth, it contains a thermocline. The tropical thermocline is typically deeper than the thermocline at higher latitudes. Polar waters, which receive relatively little solar energy, are not stratified by temperature and generally lack a thermocline because surface water at polar latitudes are nearly as cold as water at greater depths. Below the thermocline, water is very cold, ranging from −1 °C to 3 °C. Because this deep and cold layer contains the bulk of ocean water, the average temperature of the world ocean is 3.9 °C. 
Story: Keith was measuring the attributes of thermoclines. He selected two locations. One is near Miami, which is in the tropic. The other is near New York, which is in higher latitude. In total, he took four samples, sample A, sample B, sample C, and sample D. From Miami thermocline he took sample A. Then from below Miami thermocline he took sample B. From New York thermocline he took sample C. Finally, from below New York thermocline he took sample D. 
Question: Would sample B be warmer or colder than sample A?

Answer:
colder.