Task: Question Answering
Input (English): Question: In neurons once an action potential has started, a second action potential can not be triggered for a short period of time, regardless of the intensity of the stimulus applied. This period of time is known as: 
 Options:  <1> Synaptic delay. <2> Threshold depolarizing period. <3> Absolute refractory period. <4> Relative refractory period. <5> Spatial sumary.
Output (English): 3