Which is an example of an instinct? A rabbit hides when it observes a predator.
A dog wags its tail when it hears a doorbell ring.
A boy pulls his hand away after touching a hot surface.
A dolphin swims through a hoop during an amusement park show.

c A boy pulls his hand away after touching a hot surface, the other answers are all learned behaviors.

Explanation:

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.