If the concentration of salts around root cells is greater than in the cells themselves, what process draws water out of the roots?

The correct answer is osmosis. This process involves the movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. In this scenario, if the concentration of salts is greater outside the root cells than inside, water will move out of the root cells in an attempt to balance the solute concentrations on both sides of the membrane.

Osmosis is essential for maintaining proper cell turgor and overall plant health. When the concentration of salts outside the plant's roots becomes too high, it can create an environment that causes water to move out of the cells due to osmosis. This can lead to wilting and other stress responses in the plant.

Reverse osmosis, although related, refers to a process where water is forced through a semipermeable membrane in the opposite direction, typically using external pressure. Diffusion pertains to the movement of solutes from an area of higher concentration to an area of lower concentration, not specifically involving water movement across membranes. Transpiration is the process of water vapor exiting the plant through stomata, which can influence water uptake but does not directly explain the movement of water out of root cells due to salt concentration differences.