The movement of water molecules from a region of higher water potential to a region of lower water potential through a semi-permeable membrane is referred to:

Explanation

Osmosis, the correct answer, refers to the movement of water molecules from an area of higher water potential to an area of lower water potential through a semipermeable membrane. This process occurs naturally and does not require energy. Option A, Active transport, is incorrect because it involves energy use to move substances against their gradient. Option C, Diffusion, does not specifically pertain to water and does not require a semipermeable membrane. Option D, Photosynthesis, is unrelated to the transport of water molecules.