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.
--------
Question: Background Paragraph: Chlamydia may cause a burning feeling during urination. It may also cause a discharge (leaking of fluids) from the vagina or penis. But in many cases it causes no symptoms. As a result, people do not know they are infected, so they don’t go to the doctor for help. If chlamydia goes untreated, it may cause more serious problems in females. It may cause infections of the uterus, fallopian tubes, or ovaries. These infections may leave a woman unable to have children. 
Story: Two women are at an STD clinic getting tested because they feel they may have caught something from recent sexual partners they had. After getting a blood sample taken, Beth is told that she has genital herpes. The doctor tells her what to expect and how to manage the symptoms. The doctor then goes into the waiting room that Sarah is in and informs her that she has tested positive for chlamydia. Sarah is not surprised, and she begins asking questions about what she should do to help control the disease. 
Question: Who is less likely to experience an infection in their fallopian tubes?

Answer: Beth.


Question: Background Paragraph: If a solution has a higher concentration of hydronium ions than pure water, it has a pH lower than 7. A solution with a pH lower than 7 is called an acid . As the hydronium ion concentration increases, the pH value decreases. Therefore, the more acidic a solution is, the lower its pH value is. Did you ever taste vinegar? Like other acids, it tastes sour. Stronger acids can be harmful to organisms. For example, stomach acid would eat through the stomach if it were not lined with a layer of mucus. Strong acids can also damage materials, even hard materials such as glass. 
Story: In his chemistry lab David is learning about acids. He took three solutions to identify them correctly, sample A, sample B, and sample C. Sample A is a strong acid; sample B is a weak acid; and sample C is not an acid. David needs to identify the content of each sample by learning about their attributes. 
Question: Which sample would most likely damage materials, sample A or sample B?

Answer: sample A.


Question: Background Paragraph: New species develop naturally through the process of natural selection . Due to natural selection, organisms with traits that better enable them to adapt to their environment will tend to survive and reproduce in greater numbers. Natural selection causes beneficial heritable traits to become more common in a population and unfavorable heritable traits to become less common. For example, a giraffe’s neck is beneficial because it allows the giraffe to reach leaves high in trees. Natural selection caused this beneficial trait to become more common than short necks. 
Story: A biologist was in Australia making observations about the local species when he identified two distinct groups of butterflies. He found that one group of butterflies, group A, blended in with the dark oak trees that were common in the area. Butterflies in the other group, group B, however did not blend in as well and could easily be spotted by predators whenever they landed on the oak trees. 
Question: Which group of butterflies will reproduce more often?

Answer:
group A.