I know the answer is A/1 but I’m not sure how to explain it, I would like some help on the explanation part

3. The accompanying diagram represents a cell in water. Formulas of molecules that can move freely across the cell membrane are shown. Some molecules are located inside the cell and others are in the water outside the cell.



(Picture) diagram



Based on the distribution of these molecules, what would most likely happen after a period of time?

A. The concentration of O₂ will increase inside the cell.

B. The concentration of CO₂ will remain the same inside the cell.

C. The concentration of O₂ will remain the same outside the cell.

D. The concentration of CO₂ will decrease outside the cell.