In the context of principles of transmembrane transport, which statement correctly contrasts facilitated diffusion with active transport?

• A. Facilitated diffusion requires ATP hydrolysis to move solutes down their electrochemical gradient, whereas active transport does not require energy input.
• B. Facilitated diffusion can occur only through the lipid bilayer without proteins, whereas active transport always occurs through protein channels.
• C. Facilitated diffusion moves solutes down their electrochemical gradient via specific transport proteins without direct energy input, whereas active transport moves solutes against their electrochemical gradient using energy (e.g., ATP hydrolysis or coupling to another gradient).
• D. Facilitated diffusion moves solutes against their electrochemical gradient using pumps, whereas active transport moves solutes down their electrochemical gradient through open channels.

Answer: (C)