Final answer:
Amniocentesis and chorionic villus sampling (CVS) use amniotic fluid samples or cells from the placenta to gather information about the baby's genetic health.
Step-by-step explanation:
Amniocentesis and chorionic villus sampling (CVS) are prenatal tests that are used to collect samples for genetic testing. Amniocentesis involves drawing out a sample of amniotic fluid from the mother's abdomen, while CVS involves sampling cells from the placenta. Both procedures can provide information about the baby's genetic health by examining the DNA in the collected samples. Therefore, the correct answer is c) Amniotic fluid sample.