This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
Noninvasive prenatal testing (NIPT) 
Select and explain. 
A. Preconceptional gene testing on ova, B. Testing on maternal tissue, C. Maternal serum for evaluation of Down’s syndrome, D. Amniocentesis for evaluation of fetal chromosomal anomalies
C: Maternal serum for evaluation of Down’s syndrome
Answer: C: Maternal serum for evaluation of Down’s syndrome 
Explanation: Ref. The Short Textbook of Obstetrics. Page. 778
 
NON INVASIVE PRENATAL TESTING

Targeted ultrasonography
Fetal blood cells in maternal blood
Double marker and triple screening
Maternal serum estriol

INVASIVE PRENATAL TESTING

Amniocentesis
Chronic villus sampling
Cordocentesis