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
[{'content': 'In cardiac cycle, opening of mitral valve occurs at the \nSelect and explain. \nA. End of isovolumetric contraction, B. Beginning of isovolumteric relaxation, C. End of isovolumetric relaxation, D. Beginning of isovolumetric contraction', 'role': 'user'}, {'content': 'Answer: C \nExplanation: At the end of isovolumetric relaxation, when right atrial pressure becomes more than right ventricle, mitral valve opens.', 'role': 'assistant'}]