Agated channel in a cell membrane allows

A gated channel is an example of facilitated diffusion. A gated channel protein is a transport protein that opens a "gate" allowing a molecule to pass through the membrane (usually molecules too big to enter the cell by passing through the membrane itself). Gated channels have a binding site that is specific for a given molecule or ion. (meaning only certain molecules or ions can enter the channel).

its c the 3rd answer