This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Physiological Changes of Pregnancy, Subject name: Gynaecology & Obstetrics
Surfactant appears in amniotic fluid at the gestational age of: 
Select and explain. 
A. 28 wks, B. 32 wks, C. 36 wks, D. 38 wks
A: 28 wks
Answer: A: 28 wks 
Explanation: Surfactant- production stas at 20 weeks Appears (found significantly) in Amniotic fluid at 24-28 weeks