What is the procedure for performing an electrocardiogram?

The electrocardiogram is a graphic record of the heart's electrical activity detected through a series of electrodes placed on the body surface and connected to an electrocardiograph.
The objective is to obtain a graphic record of the heart's electrical activity to identify anatomical, metabolic, ionic, and hemodynamic alterations.
The procedure involves placing electrodes on the wrists, ankles, and chest, and connecting them to an electrocardiograph.
The patient should be in a supine position and avoid contact with metallic surfaces or objects during the procedure.
a. I, II, and III are correct.
b. II, III, and IV are correct.
c. I, III, and IV are correct.