Task: Question Answering
Input (English): Question: A cyclic voltammetry: 
 Options:  <1> It is based on a stationary broadcasting regime. <2> It uses macroelectrodes as working electrodes. <3> He never needs a potentiostatic system. <4> It is always done in a non-agitated solution. <5> It uses a square wave potential format as an excitation system.
Output (English): 4