Which one of the following is a matching pair?

(i)	Lub	Sharp closure of AV valves at the beginning of ventricular systole
(ii)	Dup	Sudden opening of semilunar valves at the beginning of ventricular diastole
(iii)	Pulsation of the radial artery	Valves in the blood vessels
(iv)	Initiation of the heart beat	Purkinje fibres