Definition: In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
Input: Question: The cells of the sinus node present: 
 Options:  <1> Stable membrane potential. <2> Contractile capacity <3> Depolarization faster than Purkinje fibers. <4> Depolarization mediated by Ca2 + channels. <5> Long plateau.
