Correct choice is (b) smart pad
The best I can explain: The system automatically selects three electrodes from an array of Cu/Ni fabric based electrodes patterned on a thin pad on which the patient lies. The smart pad is a system that displays a patients electrocardiogram signals without adhesive pads, wires or active intervention from a clinician. The selected electrodes are used to provide a differential 3 lead measurement of the patient’s ECG, which is then transmitted wirelessly and displayed on a laptop computer.