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.

Background Paragraph: Ionizing radiation has many practical uses in medicine, research and construction, but presents a health hazard if used improperly. Exposure to radiation causes damage to living tissue; high doses result in Acute radiation syndrome (ARS), with skin burns, hair loss, internal organ failure and death, while any dose may result in an increased chance of cancer and genetic damage; a particular form of cancer, thyroid cancer, often occurs when nuclear weapons and reactors are the radiation source because of the biological proclivities of the radioactive iodine fission product, iodine-131. However, calculating the exact risk and chance of cancer forming in cells caused by ionizing radiation is still not well understood and currently estimates are loosely determined by population based data from the atomic bombings of Hiroshima and Nagasaki and from follow-up of reactor accidents, such as the Chernobyl disaster. The International Commission on Radiological Protection states that "The Commission is aware of uncertainties and lack of precision of the models and parameter values", "Collective effective dose is not intended as a tool for epidemiological risk assessment, and it is inappropriate to use it in risk projections" and "in particular, the calculation of the number of cancer deaths based on collective effective doses from trivial individual doses should be avoided.". 
Story: Michael and Robert are scientists who work in a nuclear reactor facility. Michael was replacing a fuel rod in the nuclear reactor when a small explosion happened, causing Michael to be exposed to high doses of radiation in a short period of time.  Robert was in the adjacent room when the explosion happened, and as a result he only suffered low doses of radiation. 
Question: Who is more likely to suffer hair loss?
Michael.

Background Paragraph: Antifreeze could also be called “antiboil” because it also raises the boiling point of the water in a car radiator. Hot weather combined with a hot engine can easily raise the temperature of the water in the radiator above 100 °C, which is the boiling point of pure water. If the water boils, it could cause the engine to overheat and become seriously damaged. However, if antifreeze has been added to the water, the boiling point is much higher. For example a 50 percent antifreeze solution has a boiling point of 129 °C. Unless the water gets hotter than this, it won’t boil and ruin the engine. 
Story: Rob is an auto mechanic. He was checking the radiators of his car and truck. He put antifreeze into the car radiator, but didn't put any antifreeze into the truck radiator. He was wondering how the vehicles would fare in coming hot weather. 
Question: Which vehicle's engine would less likely be damaged, car or truck?
car.

Background Paragraph: Thermoclines, or sudden changes in temperature. Where the air temperature is higher than the water temperature, shallow water may be warmed by the air and the sunlight but deeper water remains cold resulting in a lowering of temperature as the diver descends. This temperature change may be concentrated over a small vertical interval, when it is called a thermocline.[3][4]
Where cold, fresh water enters a warmer sea the fresh water may float over the denser saline water, so the temperature rises as the diver descends.[3]
In lakes exposed to geothermal activity, the temperature of the deeper water may be warmer than the surface water. This will usually lead to convection currents.[3]. 
Story: The underwater fishing teams picked their spots early. Team Bob went at the mouth of the river, where the freshwater met the salty seawater in the hope that more turbidity from the river and more nutrients will attract more fish. Team Dan went south where they knew there was less of a thermocline, so they could catch fish without taking risks. 
Question: Which team had their crew members to fewer risks than necessary?

Dan.