Reading Comprehension 
从下列每篇短文的问题后所给的四个选择项中选出一个最佳答案。
People born in autumn live longer than those born in spring and are less likely to fall chronically(慢性地) ill when they are in their old age, according to an Austrian scientist. Based on census(人口普查) data collected from more than one million people in Austria, Denmark and Australia, scientists at the Max Planck Institute for Demographic Research in the northern German town of Rostock found the month of birth was related to life span over the age of 50. Seasonal differences in what mothers ate during pregnancy and infections(感染)occurring at different times of the year could have an impact on the health of a new-born baby and affect its life span in old age. "A mother giving birth in spring spends the last phase of her pregnancy in winter, when she will eat less vitamins than in summer”, said Gabriele Doblhammer, one of a team of scientists who carried out the research, "The mother stops breast-feeding and starts giving her baby normal food in the hot weeks of summer. Then, the baby is prone to infections of the digestive system." In Austria adults born in autumn lived about seven months longer than those born in spring; in Denmark adults with birthdays in autumn outlived those born in spring by about four months. In the southern part of the Earth, the picture was similar. Adults born in the Australian autumn lived about four months longer than those born in the Australian spring. Based on death certificates and census data the study focused on people born at the beginning of the 20th century. Doblhammer said that the seasonal pattern persists, although nutrition at all times of the year has improved since then.