阅读所给材料，从每题所给的A、B、C、D 四个选项中，选出最佳选项。
①As the weather gets warmer, there are few things that are better to do than travel. But traveling might not be that fun for everyone, especially for those who have motion sickness（晕动症）.
②Motion sickness is also called travel sickness. It is quite common for many people. Because of different ways of travel, we can also call it carsickness or seasickness. People with motion sickness feel very uncomfortable while they are moving. They feel sick, like the room around them won't stop moving. It is often believed that motion sickness happens when your senses（感官）can not understand each other well, Scientific American reported. We use different parts of our body to sense movement. Our eyes tell us if we are moving. The inner ears have a special part that helps us sense our direction and balance（方向和平衡）.
③When you move around, for example, these body parts work well together. But when you are in a car or on an airplane, your body parts don't know how to work with each other. Your inner ear tells your body that you're moving, but your eyes say you're sitting still because you can't see that you're moving. This mismatch（错配）gives us motion sickness.
④ ▲ This may be because they have certain genes（基因）that stop mismatching senses, Bethann Hromatka, a genetics scientist from the US, told the Atlantic.
⑤Although there are many ways to deal with motion sickness, scientists believe that the key is to simply try and adapt to it. For example, some astronauts do special exercises that give them a little motion sickness. After a week or two, the astronauts become used to it and don't feel uncomfortable anymore, Sam Puma, a NASA flight doctor, told the BBC.
