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
Isovolumic relaxation phase of the cardiac cycle ends with : 
Select and explain. 
A. Peak of 'C' waves, B. Opening of A.V. valve, C. Closure of semilunar valve, D. Beginning of wave.
B: Opening of A.V. valve
Answer: B: Opening of A.V. valve 
Explanation: B i.e. Opening of A.V. value Valvular event (valves) Cardiac events ECG JVP (Jugular venous Pressure curve) Opening of AV End of End of T V-Y descentQ valveQ isovolumic relaxation phaseQ waveQ (phase b/w T wave and new p wave) Closure of AV -End of diastole Later half of End of 'x' valve - Beginning of isovolumic contraction R wave descent Opening of semilunar valve End of isovolumic contractionQ ST segment Peak of 'C' wave Closure of - Beginning of Later half of semilunar valve isovolumic relaxation T wave Phase - Beginning of diastole