Task: Question Answering
Input (English): Question: The analysis by potentiometric redisolution is characterized: 
 Options:  <1> By using the square wave as an element of excitation. <2> Because the redisolution stage is carried out without agitation. <3> Because the reoxidation step is carried out by an oxidizing agent. <4> Because currents are measured in the redisolution stage. <5> Because the redisolution is carried out at constant potential.
Output (English): 3