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: Sometimes muscles and tendons get injured when a person starts doing an activity before they have warmed up properly. A warm up is a slow increase in the intensity of a physical activity that prepares muscles for an activity. Warming up increases the blood flow to the muscles and increases the heart rate. Warmed-up muscles and tendons are less likely to get injured. For example, before running or playing soccer, a person might jog slowly to warm muscles and increase their heart rate. Even elite athletes need to warm up ( Figure below ). 
Story: Steve and Jon are getting ready for a big marathon that both have been training for. Steve gets ready for the race by stretching and doing some pre-race warm ups. Jon on the other had does no think warming up helps at all, and decides to just remain seated until it is time for the race to start. 
Question: Who is less likely to get an injury during the race?
[EX A]: Steve.

[EX Q]: Background Paragraph: Hemophilia is the name of a group of hereditary diseases that affect the body's ability to control blood clotting. Hemophilia is caused by a lack of clotting factors in the blood. Clotting factors are normally released by platelets. Since people with hemophilia cannot produce clots, any cut can put a person at risk of bleeding to death. The risk of internal bleeding is also increased in hemophilia, especially into muscles and joints. This disease affected the royal families of Europe. 
Story: Two brothers took a blood test. The doctor found out that Tim had hemophilia, while his brother Rick had normal blood cells and was healthy. 
Question: Which brother had a lower risk of bleeding to death?
[EX A]: Rick.

[EX Q]: Background Paragraph: Gasoline-powered vehicles emit a lot of harmful materials. Nitrogen oxides are formed when atmospheric nitrogen reacts with oxygen at the high temperatures found in a car engine. Carbon monoxide is a by-product of incomplete combustion of hydrocarbons. Evaporated and unused fuel releases volatile hydrocarbons into the atmosphere to help form smog. The presence of a catalytic converter in the exhaust system of the car causes these materials to react and be changed into less harmful products. 
Story: Due to economic sanctions and trade embargoes, Cuban citizens primarily use cars designed in the late 1940s and early 1950s. These cars contain engines that were designed before the introduction of the catalytic converter. Meanwhile trade relations between nearby Panama and Japan have enabled the citizens of Panama to drive cars with the most up to date catalytic converter technology possible. 
Question: Which country's cars, Cuba's or Panama's, will emit less nitrogen oxides?
[EX A]:
Panama's.