The surroundings or conditions in which a person, animal, or plant lives or operates.
The natural environment encompasses all living and non-living things occurring naturally, meaning in this case not artificial. The term is most often applied to the Earth or some parts of Earth.
D.stable to slightly shrinking
From mouth/nose, the air passes to the trachea (the wind pipe), there it enters (sequentially) the bronchi, bronchioles (small pipe-like structures), alveoli (widened empty sacs), the walls of which are in close contact with the blood vessels which contain the RBCs, which in turn contain the protein--hemoglobin, which binds to the oxygen present in the freshly inhaled air, and loses the carbondioide present DISSOLVED in the blood. This bound oxygen goes to the heart (of course along with the RBCs in the blood), from there to the smaller and smaller arteries, then to the capillaries, where again oxygen is lost to the surrounding tissue fluid, from where the cells collect oxygen by simple diffusion, and lose carbon dioxide, which gets dissolved in the water present in the blood.
From here the blood, with hemoglobin poorer in oxygen, and richer again in carbondioxide goes to the venules, and veins (capillaries continue as venules), which become successively larger to become superior and inferior vena cava and enter the right atrium, and then from there the blood again goes to the lungs and comes in contact with fresh air in the alveoli.
The correct answer is: A. Water molecules will move from Side A to Side B. The solution level on Side A will fall and the solution level on Side B will rise.
Because the barrier is permeable only for water, water will move via osmosis-down the gradient (into a area of higher solute concentration). Water tends to equalize the solute concentrations of the side A with the solute concentrations of the side B.