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: Surgery
Patient is placed in trendelenburg position in air embolism in order to 
Select and explain. 
A. Trap air in Right ventricle, B. Keep left ventricular air bubble away from coronary artery ostia, C. Prevent air from passing through foramen ovale, D. Prevent air from entering left ventricle
B: Keep left ventricular air bubble away from coronary artery ostia
Answer: B: Keep left ventricular air bubble away from coronary artery ostia 
Explanation: Trendelenberg position keeps left ventricular air bubble away from coronary ostia, so that air bubbles do not enter and occlude coronary arteries.