下面有3篇短文，每篇短文后有5道题，每题后面有4个选项。清仔细阅读短文并根据短文回答其后面的问题，从4个选项中选择1个最佳答案。
第一篇

Benefits of Educating Girl The benefits of educating girls are numerous --to individual girls both when they are young and when they become adult women, to their future families, and to society as whole. Education enables women to contribute more fully to the social and economic development of their societies. A girl’s education is also an investment in future generations. The more educated a mother is, the more likely are her children --particularly her daughters -- to roll and stay in school. The higher level of education attained by women is strongly associated with lower child death. Experts believe more educated women practice better hygiene and nutrition(营养),use health services more frequently, and survive better. Woman with more schooling tend to be healthier themselves. Perhaps reflecting their improved ability to avoid frequent childbearing (分娩)and to take advantage of available health services during pregnancy(怀孕). The educational level achieved by women, like family planning services, has the most powerful influence on family size. The impact of education on family size is strongest and most consistent for women who have completed some secondary schooling. Educating girls is three times more likely to lower family size than educating boys. Education appears to affect family size in many ways. More educated women not only want fewer children than their less educated husbands, but also are more likely to use effective contraception(避孕) successfully and to limit their families to the number of children, which contribute to smaller family size. Family size is ideal and child death rates are lowest, therefore, in countries that combine strong family planning and health programs with high levels of education for women.

In what way do women contribute to the small family size according to the text