Answer:
Active transport, because energy is being used to move molecules against the concentration gradient.
Explanation:
This picture shows active transport. That just means that energy is being used (in this case, ATP) to move molecules against their gradient (meaning, from low to high concentration). Molecules "naturally" diffuse from high-->low concentration, so to move in the opposite direction requires energy input. You can tell this because there are only 2 molecules on the top side of the membrane, but on the bottom side there are 13.
Why not A: This is not necessarily water, as in osmosis, and it's not going with the gradient.
Why not C: This is not facilitated diffusion, because molecules are going against, not with, their concentration gradient.
