Deoxygenated blood obtains oxygen from the

Lungs.

Explanation:

Deoxygenated blood contains high amount of carbondioxide while oxygenated blood has oxygen in large concentration. This carbondioxide is produced in the cell in the process of cellular respiration. This deoxygenated blood is taken from the cell to the lungs through the veins. In the lungs, the carbondioxide is removed and oxygen is loaded in the blood. This oxygenated blood is again goes to the heart and distributed to all the cells.

I think it's lungs. It leaves the heart on the right side to go to the lungs