Unique feature of osmosis is that
(1) energy is required
(2) it involves movement of solutes
(3) it occurs across membranes only
(4) it is seen only in animals

Respuesta :

Answer:

I believe the answer is (3)

Explanation:

"Osmosis is a special type of diffusion, namely the diffusion of water across a semipermeable membrane"

"Osmosis only occurs with a semipermeable membrane"

Khan and sciencedirect