Answer the following question given this paragraph: 

Facilitated diffusion is the diffusion of solutes through integral membrane transport proteins. Facilitated diffusion is a type of passive transport . Even though facilitated diffusion involves transport proteins (and is essentially a transport process), it can still be considered passive transport because the solute is moving down the concentration gradient, and no input of energy is required. Facilitated diffusion utilizes proteins known as uniporters. A uniporter can be either a channel protein or a carrier protein.


Q: Because the solute is moving down the concentration gradient, and no input of energy is required, facilitated diffusion is considered what type of transport?

 Choices:

- active

- neutral

- adaptive

- passive

A:
passive
