A nurse is caring for a client who is scheduled for a maternal serum alpha-fetoprotein test at 15 weeks of gestation. The nurse provides which of the following explanations about this test to the client?

Choice A rationaleFetal lung maturity is typically assessed using amniocentesis or lecithin-sphingomyelin (L/S) ratio. Normal L/S ratio is 2: or greater.Choice B rationaleRh incompatibility is assessed using indirect Coombs test, not maternal serum alpha-fetoprotein. Normal Coombs test is negative.Choice C rationaleVarious markers of fetal well-being are assessed using biophysical profile or non-stress test, not maternal serum alpha-fetoprotein. Normal biophysical profile score is 8-10.Choice D rationaleMaternal serum alpha-fetoprotein is a screening test for neural tube defects such as spina bifida and anencephaly. Normal alpha-fetoprotein levels range from 10-150 ng/mL.