During the relative refractory period, . During the relative refractory period, . another action potential can be generated provided the stimulus is relatively smaller than the original stimulus. another action potential can be generated provided the stimulus is large enough. the flow of potassium is also depolarizing the neuron. a second action potential cannot be generated, no matter how strong the stimulus.

During the relative refractory period, another action potential can be generated provided the stimulus is large enough.

Explanation:

The relative refractory period is the time after an action potential where the sodium channels are transitioning from inactivated channels to closed ones. In other words, voltage-gated Na+ channels have two gates, an external one and an internal one. During repolarization, the outer gate is blocking the entrance, and the internal one is open. So the channel is inactivated. When the inner gate is closed, the Na+ channel is closed.

During the relative refractory period, a second action potential can happen, but the stimulus has to be large enough to do it since the membrane is hyperpolarized, that is to say, the membrane potential is more negative than the resting action potential. The cell needs more Na+ ions to produce the second action potential.

the correct answer is d