This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
[{'content': 'The detection rate of Down syndrome with first-trimester screening with NT, PAPP-A, and hCG is \nSelect and explain. \nA. 64-70%, B. 80-84%, C. 94-96%, D. 99%', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Selected Down Syndrome Screening Strategies and Their Detection Rate: Screening test Detection rate Quadruple screen 80-82% First-trimester screen NT alone 64-70% NT, hCG, PAPP-A 80-84% Integrated screening 94-96% Sequential screening Stepwise 92% Contingent 91% Cell-free DNA 91%', 'role': 'assistant'}]