For the Acquisition of a 4-Lead Tracing, Why Is the Skin

For the acquisition of a 4-lead tracing, why is the skin cleansed, dried, and shaved of hair (if necessary) prior to applying the ECG electrodes?

A) Because ECG monitoring is a sterile procedure
B) To decrease the amount of energy needed should the patient need to be defibrillated
C) To enhance the conductivity between the electrode and the skin
D) Because it makes the heart more responsive to defibrillatory shocks