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: Beginning in the late 1970’s, ozone depletion was recognized as a significant environmental issue. The most dramatic decrease in ozone occurs seasonally over the continent of Antarctica. The size and duration of the ozone hole steadily increased, with the largest hole recorded in 2006. Fortunately, most countries have recognized the danger of CFCs and dramatically curtailed their use in recent years. It is hoped that ozone depletion will slow and that the ozone layer may eventually be restored to its earlier levels. 
Story: Greg has been on an environmental awareness kick lately. He is trying to buy products that are good for the environment. While at the store, he stopped to look at some hair sprays. The Revlon brand he noticed has CFCs. The Sephora brand he noticed explicitly noted that it did not contain CFCs. 
Question: Will Revlon brand be more or less environmentally friendly than Sephora brand hair spray?
[EX A]: less.

[EX Q]: 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?
[EX A]: Salt.

[EX Q]: Background Paragraph: Greenhouse Effect: The solar energy reaching the surface of the Earth is concentrated in short wavelengths, which can easily penetrate the greenhouse gases, such as carbon dioxide and methane. The Earth, however, is cooler than the sun and it radiates its heat in the form of energy in the far infrared range. These longer wavelengths are partially absorbed by the greenhouse gases and some of the solar heat is returned to Earth. At a certain temperature these processes are in equilibrium and the surface temperature of the Earth is stable. However, if more greenhouse gases are put in the atmosphere the amount of trapped terrestrial radiation increases, leading to an increase in global temperature. 
Story: Two friends liked studying about the Earth's atmosphere. Vick studied more about the troposphere, while Frank studied more about the Greenhouse Effect. 
Question: Which friend studied less about methane?
[EX A]:
Vick.