The right answer is the second one
Answer:
What sends oxygenated blood back to the heart from the lungs?
Oxygen-rich blood flows from the lungs back into the left atrium (LA), or the left upper chamber of the heart, through four pulmonary veins. Oxygen-rich blood then flows through the mitral valve (MV) into the left ventricle (LV), or the left lower chamber.
Explanation:
Eukaryotes are larger cells with membrane-bounded organelles. Prokarotes are not that large and do not have a nucleus or any memberane-bound organelles.
B-Kidneys
The kidneys act as filters that strain urea and excess salts from the bloodstream to release them in the urine.