Which statement correctly describes an event in the cardiac cycle that comes after atrial systole?
- AA wave of excitation passes through the sinoatrial node (SAN), before spreading down to the base of the septum.
- BElectrical impulses pass from the muscles of the atria to the muscles of the ventricles to cause ventricular systole.
- CElectrical impulses pass through conducting fibres, which cause a delay before spreading to Purkyne tissue.
- DThe opening and closing of the semilunar valves occurs later than the opening and closing of the atrioventricular valves.