This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
What is the duration of a human cardiac cycle in seconds? 
Select and explain. 
A. 0.4, B. 0.8, C. 1, D. 1.6
B: 0.8
Answer: B: 0.8 
Explanation: Duration of cardiac cycle (at hea rate of 75/min) is 0.80sec. Out of which duration of systole is 0.27sec and diastole is 0.53sec.