The correct option is A 0.8 sec
The normal duration of the cardiac cycle is 0.8 second. Atrial systole - 0.1 sec. Atrial diastole - 0.7 sec. Ventricular systole - 0.3 sec. Ventricular diastole - 0.5 sec. A single cycle of cardiac activity can be divided into two basic phases - diastole and systole.