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: Medicine
[{'content': 'Cor pulmonale is: \nSelect and explain. \nA. Standstill of heart, B. Decreased cardiac output, C. Decreased venous return, D. Decreased ventricular constriction', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]