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

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

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

a plastic spoon that has a temperature of 78° f is placed into a bowl of soup that has a temperature of 84° f. which of these correctly describes what will happen?

energy as heat moves from the soup to the spoon.