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': 'Preload is determined by ? \nSelect and explain. \nA. Enddiastolic volume, B. Endsystolic volume, C. Ventricular ejection volume, D. None of the above', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Enddiastolic volume", 'role': 'assistant'}]