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: 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: The extensive grazing in Tibet lead to carbon and nitrogen loss, subject to desertification, while Nepal adopted a different approach to food production, putting nature and biodiversity first. 
Question: Which country experiences a higher level of desertification?
[EX A]: Tibet.

[EX Q]: Background Paragraph: At birth, a rattlesnake hatchling has only a small button or 'primordial rattle' which is firmly attached to the tip of the tail.[13] The first segment is added when the hatchling sheds its skin for the first time.[14] A new section is added each time the skin is shed until a rattle is formed. The rattle grows as the snake ages but segments are also prone to breaking off and hence the length of a rattle is not a reliable indicator of the age of a snake.[15]. 
Story: Dan found three rattle snakes: one only had one rattle, the second snake had 4 rattles and the third snake had seven rattles on its tail. 
Question: Which snake had more segments, the first or the second snake Dan found?
[EX A]: the second.

[EX Q]: Background Paragraph: Hypertension , which is also called "high blood pressure," occurs when a person’s blood pressure is always high. Hypertension is said to be present when a person's systolic blood pressure is always 140 or higher, and/or if the person's diastolic blood pressure is always 90 or higher. Having hypertension increases a person’s chance for developing heart disease, having a stroke, or suffering from other serious cardiovascular diseases. Hypertension often does not have any symptoms, so a person may not know that he or she has high blood pressure. For this reason, hypertension is often called the "silent killer." Treatments for hypertension include diet changes, exercise, and medication. Foods thought to lower blood pressure include skim milk, spinach, beans, bananas and dark chocolate. 
Story: Dirk went to the doctor because he was feeling dizzy. The doc told him he has Hypertension. His wife,  Mary went to the doctor the following week, and the doc said her blood pressure was normal. 
Question: Which patient had a smaller chance of having a stroke?
[EX A]:
Mary.