According to statistics, about 20 million people in the U. S. are affected by mite allergies. Research results from a university show that compared to other species, the eastern and western coasts of the United States are mites 'paradise, while the western inland is mites' hell. Living in a humid environment. In this regard, experts suggest, "If you are allergic to mites, living in the dry and high altitude areas of the United States and Canada is definitely a good choice. ". Which of the following, if true, is the most effective support for the above expert advice? ['Much more people are allergic to mites living in the western United States than in the eastern United States.', 'Mattresses, blankets and furniture moved from wet areas to dry areas can also breed mites.', 'Many people who are allergic to mites report that their allergy symptoms have decreased during business trips in the western United States.', 'By covering the mattress and blanket with a hypoallergenic cover and changing the sheets every week, it can effectively suppress mites.']