The incidence of coronary heart disease in developed countries is about three times that of developing countries. Some people think that this is mainly due to people's high fat, high protein and high-calorie food intake in developed countries. Few people have the conditions to have this kind of "rich disease" in developing countries. In fact, this view is difficult to establish. At present, the average life expectancy in developed countries is higher than 70 years, while the average life expectancy in developing countries is less than 50 years. Which of the following, if true, would best strengthen the above rebuttal? ['Statistics show that patients with coronary heart disease are relatively concentrated in the middle and old age groups, that is, those over 45.', 'At present, patients with coronary heart disease are younger.', "People's high-fat, high-protein, and high-calorie food intake in developing countries, both in total and per capita, is increasing year by year.", 'Compared with developing countries, people in developed countries have a higher common sense of prevention and treatment of coronary heart disease and better medical conditions.']