Identify the statement that best describes the characteristics of a voltage-gated ion channel.
a. When a voltage change occurs on the plasma membrane, these channels are able to have ligands bind to them to cause them to open.
b. They open and close in response to a specific voltage change across the plasma membrane.
c. ATP causes these channels to open and force ions in and out of the cell, which creates a voltage on the plasma membrane.
d. The binding of a ligand to these channels causes a voltage change to occur on the cell's plasma membrane.