Task: Question Answering
Input (English): Question: In an electrochemical cell, the supporting electrolyte serves to: 
 Options:  <1> That the principle of electroneutrality in the dissolution is fulfilled. <2> That their ions are electrolized preferably in order to prevent the consumption of electroactive substance. <3> That in the cell there is transport by migration, in order to achieve greater sensitivity. <4> That the solution has an adequate electrical conductivity. <5> Encourage transport by diffusion of the electroactive substance.
Output (English): 4