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
At the end of isometric relaxation phase : 
Select and explain. 
A. Atrioventricular valves open, B. Atrioventricular valves close, C. Corresponds to peak of "C" wave in JVP, D. Corresponds to T wave in ECG
A: Atrioventricular valves open
Answer: A: Atrioventricular valves open 
Explanation: A i.e. Atrioventricular value open