Which two heart chambers contain oxygenated blood?

The answer is left atrium and left ventricle. 

Basically, the blood which just gone through the gas exchange at the lungs will be transported to the left atrium, through the pulmonary vein. At this time, the blood is filled with oxygen and nutrients. The blood from the left atrium will soon flow down to the left ventricle when the heart relaxes. During this process, the blood is not used in any ways so the content should be very similar to those in the left atrium. Those blood are ready to be transported to all the other organs (except lungs) to provide oxygen and nutrients through the aorta. 

Therefore, the 2 chambers that contain oxygenated blood are the left atrium and left ventricle. 

True it's the strategy

Well a pediatrician is a children’s doctor and a obstetrician is a doctor that delivers babies and cares for pregnant women.