Question

what happens as a result of protein channels being selective towards certain molecules?
the molecules will teleport around the channels.
only one type of molecule can pass through a certain protein channel.
any molecule can pass through a protein channel.

Explanation:

Protein channels' selectivity means they allow only specific molecules. Teleportation is a sci - fi concept not related to protein channels. And if any molecule could pass, there would be no selectivity.

Answer:

Only one type of molecule can pass through a certain protein channel.