Answer the following question given this paragraph: 

Osmosis is the diffusion of water molecules across a semipermeable membrane and down a concentration gradient. They can move into or out of a cell, depending on the concentration of the solute.


Q: What is the diffusion of water molecules across a semipermeable membrane?

 Choices:

- organelle motion

- electrolysis

- active transport

- osmosis

A:
osmosis
