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: One interesting thing that has been found in plants that are consistently exposed to drought, is their ability to form a sort of "memory". In a study by Tombesi et al., they found plants who had previously been exposed to drought were able to come up with a sort of strategy to minimize water loss and decrease water use. They found that plants who were exposed to drought conditions actually changed they way the regulated their stomates and what they called "hydraulic safety margin" so as to decrease the venerability of the plant. By changing the regulation of stomata and subsequently the transpiration, plants were able to function better in situations where the availability of water decreased.
Story: Drought is major concern in the Midwest. To confront the problem scientists are trying to develop drought-resistant crops. To that end, they took a plant that was not exposed to drought. They labeled it as plant A. Then they took a similar plant, and repeatedly exposed it to drought. They labeled it as plant B. They wanted to find out what makes a plant drought-resistant.
Question: Which plant would function worse with less water, plant A or plant B?
[EX A]: plant A.

[EX Q]: Background Paragraph: Besides anthropogenic productivity of the land, the biodiversity of degraded land also declines, as previously mentioned.[12] With less biodiversity, this ecosystem is less adaptable to when disasters strike it[11][8] It has a smaller available food supply, in terms of plants, for animals, who then may die out or more likely may relocate. Proof of this decline is that presently 15-20% of Tibetan Plateau species are now considered endangered; and now because of this animal and plant absence, the soil quality of these degraded lands is very poor.[1] It does not hold the necessary nutrients, such as water, nitrogen, and carbon, essential to either supporting life or inviting life back to that land.[6] As a result of such carbon and nitrogen loss in the Tibetan Plateau, $8,033/ha and $13,315/ha were respectively lost in economic terms. Soils are further weakened by dust storms whose frequency increases because of degradation.[11][4] Erosion of soil becomes a bigger problem, since no longer are there as many plants to anchor in the soil. In the northern Chinese province alone, 400 million are affected every year with an associated 54 billion yuan of annual economic loss due to grassland degradation.
Story: Xi province started sustainable agriculture and permaculture 40 years ago, while Huan province still uses conventional methods of cultivation. Animals grazing the fields extensively lead to desertification, the loss of carbon and nitrogen in the soil, and other problems. Permaculture was beneficial in Xi province, they re-built 10 inches of top soil in 10 years which is 6 times faster than the natural rate, which lead to a more diverse ecosystem and more biodiversity.
Question: Which province contributed to soil degradation less?
[EX A]: Xi province.

[EX Q]: Background Paragraph: Noble gases are also used to fill the glass tubes of lighted signs like the one in the Figure below . Although noble gases are chemically nonreactive, their electrons can be energized by sending an electric current through them. When this happens, the electrons jump to a higher energy level. When the electrons return to their original energy level, they give off energy as light. Different noble gases give off light of different colors. Neon gives off reddish-orange light, like the word "Open" in the sign below. Krypton gives off violet light and xenon gives off blue light.
Story: John wanted to make some lighted signs for his business. To that end, he chose noble gases, neon, krypton, and xenon. First, he kept the noble gases in containers. He called it step A. Then he passed electric current through them. He called it step B. In the process, he came up with three signs, sign A, sign B, and sign C. Sign A used neon. Sign B used krypton, and sign C used xenon.
Question: In which step the the electrons would jump to higher energy level, step A or step B?
[EX A]:
step B.