What responses it takes to open or close ion channels

Depolarization and Hyperpolarization occurs when ion channels open and close.

Explanation:

In some specific part of the membrane of neuron, the potential of the membrane becomes less positive it is that results in Hyperpolarization. Depolarization is in contrast with this, since the potential of the membrane will become less negative in this type. these two types occurs during the opening and closing of ion channels that are present in the membrane. This will result making the ions either entering the cell or exiting the cell.

hyperpolarization occurs when the channels opens and resulting in letting the ions that are positive to exit out of the cell. When the channel opening results in letting the positively charged ions to get into the cell, then depolarization occurs. The channel opening and closing highly depends on the binding nature of the molecules that are signalling.

the answer to your question is b