At 35 Weeks of Pregnancy a Woman Experiences Preterm Labor

At 35 weeks of pregnancy a woman experiences preterm labor.Tocolytics are administered and she is placed on bed rest,but she continues to experience regular uterine contractions,and her cervix is beginning to dilate and efface.What would be an important test for fetal well-being at this time?

A) Percutaneous umbilical blood sampling (PUBS)
B) Ultrasound for fetal size
C) Amniocentesis for fetal lung maturity
D) Nonstress test (NST)