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.

[Q]: Background Paragraph: Cancer is a disease that causes cells to divide out of control. Normally, the body has systems that prevent cells from dividing out of control. But in the case of cancer, these systems fail. Cancer is usually caused by mutations. Mutations are random errors in genes. Mutations that lead to cancer usually happen to genes that control the cell cycle. Because of the mutations, abnormal cells divide uncontrollably. This often leads to the development of a tumor. A tumor is a mass of abnormal tissue. As a tumor grows, it may harm normal tissues around it. Anything that can cause cancer is called a carcinogen . Carcinogens may be pathogens, chemicals, or radiation. 
Story: A team of scientists studied two groups of mice. Group C was exposed to carcinogens, while group N was not. 
Question: Which group of mice had fewer abnormal cells divide uncontrollably?
[A]: group N.


[Q]: Background Paragraph: As Figure above shows, the distance between particles is much smaller for the solid and liquid states than for the gas state. In the solid state, particles are fixed in place, while particles are more free to move in the liquid and gas states. The particles in the solid and liquid states “stick together,” but in the gas state, they move freely about the container. In general, it requires energy to separate individual particles. If we want to make a solid adopt a liquid form, we can add energy in the form of heat, increasing the temperature of the substance. Conversely, if we want to convert a substance from a gas to a liquid or from a liquid to a solid, we remove energy from the system and decrease the temperature. Pressure also plays an important role in changes of state, which will be discussed later on. We will study these difference in greater detail in the chapter States of Matter. 
Story: Thomas and Alexander are freshman students in an introductory chemistry laboratory course at their local college. In this week's experiment, both Thomas and Alexander will be starting their experiments with liquid water. They both follow different experimental protocols, and at the end of the experiment Thomas discovers ice in his reaction flask, while Alexander discovers steam in his reaction flask. 
Question: Which person must have increased the temperature of their reaction?
[A]: Alexander.


[Q]: Background Paragraph: Individuals living in large groups may be safer from attack because the predator may be confused by the large group size. As the group moves, the predator has greater difficulty targeting an individual prey animal. The zebra has been suggested by the zoologist Martin Stevens and his colleagues as an example of this. When stationary, a single zebra stands out because of its large size. To reduce the risk of attack, zebras often travel in herds. The striped patterns of all the zebras in the herd may confuse the predator, making it harder for the predator to focus in on an individual zebra. Furthermore, when moving rapidly, the zebra stripes create a confusing, flickering motion dazzle effect in the eye of the predator. 
Story: Two packs of lions were hunting large herbivores.  The Simba pack was ambushing wounded individual prey animals, while the Mobutu pack followed large groups of zebras and other grazers. 
Question: Which pack was confused more often by the striped patterns of the zebras?
[A]:
Mobutu.