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': 'It is considered as the bluntly rounded portion of the heart \nSelect and explain. \nA. Aorta, B. Apex, C. Base, D. Pericardium', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B:\xa0The blunt, rounded point of the heart is the\xa0apex.\nA:\xa0The\xa0aorta\xa0is the largest artery that\xa0carries blood from the left ventricle to the body.\nC:\xa0The larger, flat portion at the opposite is the\xa0base.\nD.\xa0The\xa0pericardium\xa0is also called the\xa0pericardial sac.\xa0It has a fibrous outer layer and a thin inner layer that surrounds the heart.', 'role': 'assistant'}]