Please answer the question on the picture

b even if hypotheses are not supported by data they can still be valuable

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

read more on -

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.