Which of the Following Describes a Relationship Between Body Weight

Which of the following describes a relationship between body weight and pregnancy?

A) Overweight women bear the greatest number of low-birth-weight infants
B) Weight gain during pregnancy is the sole determinant of fetus weight at birth
C) The increased incidence of neural-tube defects of infants born to obese women is due primarily to folate insufficiency
D) Underweight women who gain 30 lbs during pregnancy tend to birth smaller babies than heavier women who gain 30 lbs