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': 'Cardiac output decreases during: \nSelect and explain. \nA. High Environmental temperature, B. Anxiety and excitement, C. Eating, D. Standing from lying position', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. Standing from lying position', 'role': 'assistant'}]