参考答案：D

解析：推理判断题。文章倒数第二段“Many of those without health insurance tend to postpone medical care for chronic problems，though they may go to hospital emergency facilities in a crisis”说大部分没有健康保险的人在患慢性病时会推迟医疗，只在危急时候才去医院救治，但并未说他们一点不关注自己的身体健康，所以排除[B]；倒数第三段第二句话“...45 million in the US did not have health insurance last year，...a rise of 5.2 million since the year of 2000”只是说美国不是全民都有医疗保险，去年有520万人没有医保，有的只有部分医保，而并不是说所有穷人都没有医疗保险，所以排除选项[A]。而选项[C]文章没有提及；根据文章倒数第二段“they may go to hospital emergency facilities in a crisis”确定答案为选项[D]。