This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET Jan 2020, Subject name: Pediatrics
In a fetus highest oxygen concentration is found in? 
Select and explain. 
A. Inferior vena cava, B. Superior vena cava, C. Left ventricle, D. Ascending aoa
A: Inferior vena cava
Answer: A: Inferior vena cava 
Explanation: Among the following options, highest oxygen conc is found in IVC Saturation of Oxygen in fetal structures - Umbilical vein - 80% (PO2 of 30-35 mm Hg ) ( Max. in entire body of fetus ) Inferior vena cava - 70% (PO2 of 26-28 mm Hg) Left ventricle - 65% Right Ventricle - 55-60% Umbilical aery - very low SVC - (PO2 of 12-14 mm Hg)