Final answer:
Facilitated diffusion does not require membrane proteins and is a passive transport process that occurs with the help of carrier or channel proteins.A. Facilitated diffusion
Step-by-step explanation:
Facilitated diffusion does not require membrane proteins. Facilitated diffusion is a passive transport process that occurs when molecules or ions move across a membrane with the help of specific transmembrane proteins called carrier proteins or channel proteins. Unlike active transport, which requires energy and membrane proteins such as ion pumps, facilitated diffusion moves substances down their concentration gradient without the need for energy input or membrane proteins.