I will take a stab at it, but there are not equations, did you forget them?
All except for C. And it's good for the environment.
Answer:
B. Solvent
Explanation:
In osmosis, water always moves from low solute concentration to high solute concentration. SOLUTE NEVER MOVES AS IT CANNOT PASS THE SELECTIVELY PERMEABLE MEMBRANE. alot of caps but need to stress this concept cuz otherwise this concept gets very confusing