企业的生产经营管理水平的高低取决于能否保证生产要素合理流动和生产要素优化组合水平的高低。

A client who is planning a pregnancy asks the nurse about ways to promote a healthy pregnancy. Which of the following would be the nurse’s best response（）

A. "Pregnancy is a human process; you don’t have to worry. "
B. "You practice good health habits; just follow them and you’ll be fine. "
C. "There is nothing you can do to have a healthy pregnaney; it’s all up to nature. "
D. "Folic acid, 400 mcg(1mcg= 10μg), improves pregnancy outcomes by preventing certain complications. "