单选题 Why is it forgivable for people to hope that they will live longer in the future than now?

A、 Because people want to live as long as possible,
B、 Because life expectancy has doubled since the mid-19th century.
C、 Because many people live past 100 and the oldest individuals have reached more than 100.
D、 Because great progress is made in medicine and health sciences during the past 150 years.

【正确答案】 D

【答案解析】根据文章第一段第二句可知由于过去150年间医药和健康科学领域所取得的巨大进步，人们有理由希望将来有一天人类尽管不可能永远活着，至少可以比现在活得长一些。[A]、[B]和[C]都是本段所描述的一个事实，但不是本题所问事实的原因。