Amy and Keith, Both in Their Mid-Twenties, Have Decided to Have

Amy and Keith, both in their mid-twenties, have decided to have a baby. Both are in good health and are physically active, although Keith is a smoker. Amy maintains her weight at about 125 pounds. While they know that parenting is a big responsibility, they are excited about the idea of becoming parents. The one thing that they are concerned about is the history of genetic illnesses that exists in each of their families. After 6 month of not being successful in conceiving, Amy is concerned that she may be infertile. She wants to see a fertility specialist. Because of Amy's and Keith's concerns about genetic illnesses, they make plans to have

A) a sonogram at about 16 weeks' gestation.
B) an amniocentesis at about 10 weeks' gestation.
C) a triple marker screening prior to 12 weeks' gestation.
D) chorionic villi sampling at about 10 weeks' gestation.